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1

650 W pulse generator for ultra-wideband (UWB) radar application  

Microsoft Academic Search

A 650 W pulse generator for ultra-wideband (UWB) radar application is presented. Key device is a npn silicon power transistor operating in the avalanche mode. After optimizing the circuit parameters and the bias conditions of the pulse generator, ultra-short electrical pulses with a peak value of 650 W, terminated into an optimum load of 5 ohms, and a pulse width

Ahmed Abbas H. Ameri; Gunter Kompa; Axel Bangert

2011-01-01

2

An Ultra-Wideband (UWB) pulse dispersion study for antennas in sensor network applications  

Microsoft Academic Search

UWB pulse dispersion studies performed with antennas aligned in a linear co-polarized fashion are inadequate for many sensor network applications, as the antennas may in practice have arbitrary orientations with respect to each other. Variations of the pulse response at different antenna orientations may significantly affect data integrity. In this work it was found that a circular monopole geometry performed

Q. Bonds; T. Weller; H. Arslan

2007-01-01

3

Ultra Wideband (UWB) communication vulnerability for security applications.  

SciTech Connect

RF toxicity and Information Warfare (IW) are becoming omnipresent posing threats to the protection of nuclear assets, and within theatres of hostility or combat where tactical operation of wireless communication without detection and interception is important and sometimes critical for survival. As a result, a requirement for deployment of many security systems is a highly secure wireless technology manifesting stealth or covert operation suitable for either permanent or tactical deployment where operation without detection or interruption is important The possible use of ultra wideband (UWB) spectrum technology as an alternative physical medium for wireless network communication offers many advantages over conventional narrowband and spread spectrum wireless communication. UWB also known as fast-frequency chirp is nonsinusoidal and sends information directly by transmitting sub-nanosecond pulses without the use of mixing baseband information upon a sinusoidal carrier. Thus UWB sends information using radar-like impulses by spreading its energy thinly over a vast spectrum and can operate at extremely low-power transmission within the noise floor where other forms of RF find it difficult or impossible to operate. As a result UWB offers low probability of detection (LPD), low probability of interception (LPI) as well as anti-jamming (AJ) properties in signal space. This paper analyzes and compares the vulnerability of UWB to narrowband and spread spectrum wireless network communication.

Cooley, H. Timothy

2010-07-01

4

Ultra-Wideband (UWB) signal localization using a vehicle-sized array  

Microsoft Academic Search

This paper describes a time-difference-of-arrival (TDOA) based algorithm to localize short-pulse ultra-wideband (UWB) signals using a vehicle-sized multiple-antenna array. The algorithm uses a generalized cross-correlation method in conjunction with novel imaging and image combining techniques for computing estimates of the transmitter position. Experiments were performed in a suburban woods to obtain real data for testing the algorithms; this paper describes

Catherine M. Keller; Derek P. Young

2005-01-01

5

See-through-wall imaging using ultra wideband short-pulse radar system  

Microsoft Academic Search

See-through-wall imaging radar is a unique application of ultra wideband communication that can provide soldiers and law enforcement officers with an enhanced situation awareness. We have developed an ultra-wideband high-resolution short pulse imaging radar system operating around 10 GHz, where two essential considerations are addressed: the effect of penetrating the walls; the pulse fidelity through the UWB components and antennas

Yunqiang Yang; A. E. Fathy

2005-01-01

6

A novel UWB pulse generator  

Microsoft Academic Search

A novel ultra wideband (UWB) pulse generator is proposed and implemented in this paper. The design is based on the transistor avalanche effect. The circuit employs an existing ultra-wideband pulse generation circuit as a trigger. An inductor is connected in series with the collector of a bipolar junction transistor (BJT) to accelerate reservoir capacitor charging. This efficiently reduces the output

Hao Zhang; Xing Liu; Na Li; T. Aaron Gulliver

2011-01-01

7

Post-Compensation of Ultra-Wideband Antenna Dispersion Using Microwave Photonic Phase Filters and Its Applications to UWB Systems  

Microsoft Academic Search

We demonstrate experimental post-compensation of ultra-wideband (UWB) antenna dispersion at a receiver front-end by using programmable microwave photonic phase filtering. After the received RF signal is modulated onto an optical carrier, we utilize a hyperfine resolution optical pulse shaper to apply the conjugate of its spectral phase in the optical domain. After optical-to-electronic conversion, this yields an electrical waveform, which

Ehsan Hamidi; Andrew M. Weiner

2009-01-01

8

Ultra-wideband (UWB) bandpass filters using multiple-mode resonator  

Microsoft Academic Search

A novel microstrip-line ultra-wideband (UWB) bandpass filter is proposed and implemented using a multiple-mode resonator (MMR), aiming at transmitting the signals in the whole UWB passband of 3.1-10.6GHz. In the design, the first three resonant frequencies of this MMR are properly adjusted to be placed quasiequally within the UWB. Then, the parallel-coupled lines at the two sides are longitudinally stretched

Lei Zhu; Sheng Sun; Wolfgang Menzel

2005-01-01

9

Capacity of PPM ultra-wideband communications with inter pulse interference  

Microsoft Academic Search

We study the information theoretic capacity of pulse position modulation (PPM) ultra-wideband (UWB) communications for single user channels. The capacity is studied with a link impulse response with delay spread and inter pulse interference (IPI). The objective is to consider the effect of IPI on capacity and quantify the capacity with IPI. An expression for the signal-to-noise ratio is developed

Reza Pasand; John Nielsen; Abu B. Sesay

2004-01-01

10

Next Generation Ultra-Wideband (UWB) Intrusion Detection Radar.  

National Technical Information Service (NTIS)

This report describes the theory and development of an ultrawideband (UWB) electronic scanning radar (ESR) using a linear array of 10 microwave sources for intrusion detection application. Each source produces a 1 kW peak S band pulse having a duration of...

G. F. Ross

1996-01-01

11

Timing synchronization for ultra-wideband (UWB) multi-band OFDM systems  

Microsoft Academic Search

An algorithm based on distinguishing the first significant multipath (FTA) is proposed to address the critical issue of symbol timing synchronization in Ultra wideband (UWB) Multi-band OFDM (MB-OFDM) systems. The algorithm attempts to locate the frame synchronization sequence and pinpoint the exact start of the Fast Fourier Transform (FFT) window by first accumulating multipath energies and then discerning for first

Chin Wee Yak; Zhongding Lei; S. Chattong; Thiang Tjeng Tjhung

2005-01-01

12

Timing synchronization and frequency offset estimation for Ultra-Wideband (UWB) MultiBand OFDM systems  

Microsoft Academic Search

An algorithm based on distinguishing the first significant multipath (FTA) is proposed to address the critical issue of symbol timing synchronization and carrier frequency offset estimation in ultra wideband (UWB) multi-band OFDM (MB-OFDM) systems. FTA pinpoints the frame synchronization sequence and the start of its fast Fourier transform (FFT) window by accumulating multipath energies and then discerning for first significant

Chin Wee Yak; Zhongding Lei; S. Chattong; Tjeng Thiang Tjhung

2005-01-01

13

Ultra-wideband, short-pulse ground-penetrating radar: simulation and measurement  

Microsoft Academic Search

Ultra-wideband (UWB), short-pulse (SP) radar is investigated theoretically and experimentally for the detection and identification of targets buried in and placed atop soil. The calculations are performed using a rigorous, three-dimensional (3D) method of moments algorithm for perfectly conducting bodies of revolution. Particular targets investigated theoretically include anti-personnel mines, anti-tank mines, and a 55-gallon drum, for which the authors model

Stanislav Vitebskiy; Lawrence Carin; Marc A. Ressler; Francis H. Le

1997-01-01

14

Ultra-wideband transmitter research  

Microsoft Academic Search

The generation of ultra-wideband (UWB) pulses is a challenging problem that involves generating pulses with fast rise times on the order of 100 ps and voltages of more than 500 kV. Pulsewidths from 130 ps to a few nanoseconds (ns) are possible. A critical step involves switching high voltages with precision. The use of both gas and oil for the

Forrest J. Agee; Carl E. Baum; William D. Prather; Jane M. Lehr; J. P. O'Loughlin; J. W. Burger; J. S. H. Schoenberg; D. W. Scholfield; R. J. Torres; J. P. Hull; J. A. Gaudet

1998-01-01

15

FDTD analysis of a gigahertz TEM cell for ultra-wideband pulse exposure studies of biological specimens  

Microsoft Academic Search

Gigahertz transverse electromagnetic (GTEM) transmission cells have been previously used to experimentally study exposure of biological cells to ultra-wideband (UWB), monopolar, electromagnetic pulses. Using finite-difference time-domain (FDTD) simulations we examine the time-dependent electric field waveforms and energy dose spatial distributions within a finite volume of biological cell culture medium during these experiments. The simulations show that when one or more

Zhen Ji; C. Hagness; H. Booske; Satnam Mathur; Martin L. Meltz

2006-01-01

16

Ultra-wideband receiver  

DOEpatents

An ultra-wideband (UWB) receiver utilizes a strobed input line with a sampler connected to an amplifier. In a differential configuration, {+-}UWB inputs are connected to separate antennas or to two halves of a dipole antenna. The two input lines include samplers which are commonly strobed by a gating pulse with a very low duty cycle. In a single ended configuration, only a single strobed input line and sampler is utilized. The samplers integrate, or average, up to 10,000 pulses to achieve high sensitivity and good rejection of uncorrelated signals. 21 figs.

McEwan, T.E.

1996-06-04

17

Ultra-wideband receiver  

DOEpatents

An ultra-wideband (UWB) receiver utilizes a strobed input line with a sampler connected to an amplifier. In a differential configuration, [+-] UWB inputs are connected to separate antennas or to two halves of a dipole antenna. The two input lines include samplers which are commonly strobed by a gating pulse with a very low duty cycle. In a single ended configuration, only a single strobed input line and sampler is utilized. The samplers integrate, or average, up to 10,000 pulses to achieve high sensitivity and good rejection of uncorrelated signals. 16 figs.

McEwan, T.E.

1994-09-06

18

Ultra-wideband receiver  

DOEpatents

An ultra-wideband (UWB) receiver utilizes a strobed input line with a sampler connected to an amplifier. In a differential configuration, .+-.UWB inputs are connected to separate antennas or to two halves of a dipole antenna. The two input lines include samplers which are commonly strobed by a gating pulse with a very low duty cycle. In a single ended configuration, only a single strobed input line and sampler is utilized. The samplers integrate, or average, up to 10,000 pulses to achieve high sensitivity and good rejection of uncorrelated signals.

McEwan, Thomas E. (Livermore, CA)

1994-01-01

19

Ultra-wideband receiver  

DOEpatents

An ultra-wideband (UWB) receiver utilizes a strobed input line with a sampler connected to an amplifier. In a differential configuration, .+-.UWB inputs are connected to separate antennas or to two halves of a dipole antenna. The two input lines include samplers which are commonly strobed by a gating pulse with a very low duty cycle. In a single ended configuration, only a single strobed input line and sampler is utilized. The samplers integrate, or average, up to 10,000 pulses to achieve high sensitivity and good rejection of uncorrelated signals.

McEwan, Thomas E. (Livermore, CA)

1996-01-01

20

Emerging Communication Technologies (ECT) Phase 2 Report. Volume 3; Ultra Wideband (UWB) Technology  

NASA Technical Reports Server (NTRS)

The Emerging Communication Technology (ECT) project investigated three First Mile communication technologies in support of NASA s Second Generation Reusable Launch Vehicle (2nd Gen RLV), Orbital Space Plane, Advanced Range Technology Working Group (ARTWG) and the Advanced Spaceport Technology Working Group (ASTWG). These First Mile technologies have the purpose of interconnecting mobile users with existing Range Communication infrastructures. ECT was a continuation of the Range Information System Management (RISM) task started in 2002. RISM identified the three advance communication technologies investigated under ECT. These were Wireless Ethernet (Wi-Fi), Free Space Optics (FSO), and Ultra Wideband (UWB). Due to the report s size, it has been broken into three volumes: 1) Main Report 2) Appendices 3) UWB

Bastin, Gary L.; Harris, William G.; Chiodini, Robert; Nelson, Richard A.; Huang, PoTien; Kruhm, David A.

2003-01-01

21

A low power Pulse Frequency Modulated UWB radar transmitter concept based on switched injection locked harmonic sampling  

Microsoft Academic Search

Pulse Frequency Modulated ultra-wideband (PFM-UWB) radar signals have been introduced as a very capable option for UWB ranging and wireless local positioning. PFM-UWB signals allow for simple correlating receivers and for a very efficient use of the UWB spectral mask. The generation of pulse frequency modulated (PFM) ultra-wideband (UWB) signals usually requires a fast tunable RF-VCO and good linear RF

Christian Carlowitz; Alexander Esswein; Robert Weigel; Martin Vossiek

2012-01-01

22

Rapid Synchronization of Ultra-Wideband Transmitted-Reference Receivers.  

National Technical Information Service (NTIS)

Time synchronization is a major challenge and a rich area of study in ultra-wideband (UWB) communication systems. Transmitted- reference (TR) receivers avoid the stringent synchronization requirements that exist in conventional pulse detection schemes. Ho...

F. Nekoogar F. Dowla A. Spiridon

2004-01-01

23

Adiabatic and fast passage ultra-wideband inversion in pulsed EPR  

NASA Astrophysics Data System (ADS)

We demonstrate that adiabatic and fast passage ultra-wideband (UWB) pulses can achieve inversion over several hundreds of MHz and thus enhance the measurement sensitivity, as shown by two selected experiments. Technically, frequency-swept pulses are generated by a 12 GS/s arbitrary waveform generator and upconverted to X-band frequencies. This pulsed UWB source is utilized as an incoherent channel in an ordinary pulsed EPR spectrometer. We discuss experimental methodologies and modeling techniques to account for the response of the resonator, which can strongly limit the excitation bandwidth of the entire non-linear excitation chain. Aided by these procedures, pulses compensated for bandwidth or variations in group delay reveal enhanced inversion efficiency. The degree of bandwidth compensation is shown to depend critically on the time available for excitation. As a result, we demonstrate optimized inversion recovery and double electron electron resonance (DEER) experiments. First, virtually complete inversion of the nitroxide spectrum with an adiabatic pulse of 128 ns length is achieved. Consequently, spectral diffusion between inverted and non-inverted spins is largely suppressed and the observation bandwidth can be increased to increase measurement sensitivity. Second, DEER is performed on a terpyridine-based copper (II) complex with a nitroxide-copper distance of 2.5 nm. As previously demonstrated on this complex, when pumping copper spins and observing nitroxide spins, the modulation depth is severely limited by the excitation bandwidth of the pump pulse. By using fast passage UWB pulses with a maximum length of 64 ns, we achieve up to threefold enhancement of the modulation depth. Associated artifacts in distance distributions when increasing the bandwidth of the pump pulse are shown to be small.

Doll, Andrin; Pribitzer, Stephan; Tschaggelar, René; Jeschke, Gunnar

2013-05-01

24

Ultra-wideband radar using Fourier synthesized waveforms  

Microsoft Academic Search

Traditional methods of ultra-wideband (UWB) radar signal generation suffer from several disadvantages such as low antenna radiation efficiency and lack of accurate control of signal parameters like pulse shape, pulse repetition interval (PRI), and its spectrum. UWB signals can be generated by expanding the desired radar waveform in a Fourier series and then synthesizing the waveform by generating the individual

Gurnam Singh Gill

1997-01-01

25

Space-Time Coding for Multiuser Ultra-Wideband Communications  

Microsoft Academic Search

In this paper, we present the construction of full rate, fully diverse, and totally real space-time (ST) codes for ultra- wideband (UWB) transmissions. In particular, we construct two families of codes adapted to real carrierless UWB communica- tions that employ pulse position modulation, pulse amplitude modulation, or a combination of the two. The first family encodes adjacent symbols and is

Chadi Abou-rjeily; Norbert Daniele; Jean-claude Belfiore

2006-01-01

26

Joint Pulse and Symbol Level Acquisition of UWB Receivers  

Microsoft Academic Search

Synchronization is a key issue for ultra-wideband (UWB) radios. Most UWB receivers require a sub-nanosecond level synchronization accuracy for pulse detection, usually leading to a very long acquisition time. In this paper, we propose a novel acquisition algorithm for UWB receivers, which jointly achieves pulse acquisition (PA) and symbol timing in a short time. Novel and practical error-resistant approaches are

Ning He; Cihan Tepedelenlioglu

2008-01-01

27

Sensing through the wall imaging using the Army Research Lab ultra-wideband synchronous impulse reconstruction (UWB SIRE) radar  

NASA Astrophysics Data System (ADS)

The U.S. Army Research Laboratory (ARL), as part of a mission and customer funded exploratory program, has developed a new low-frequency, ultra-wideband (UWB) synthetic aperture radar (SAR). The radar is capable of penetrating enclosed areas (buildings) and generating SAR imagery. This supports the U.S. Army's need for intelligence on the configuration, content, and human presence inside these enclosed areas. The radar system is mounted on a ground based vehicle traveling along the road and is configured with an array of antennas pointing toward the enclosed areas of interest. This paper will describe an experiment conducted recently at Aberdeen Proving Ground (APG), Maryland. In this paper we briefly describe the UWB SIRE radar and the test setup in the experiment. We will also describe the signal processing and the image techniques used to produce the SAR imagery. Finally, we will present SAR imagery of the building and its internal structure from different viewing directions.

Nguyen, Lam; Ressler, Marc; Sichina, Jeffrey

2008-05-01

28

A computational study of ultra-wideband versus narrowband microwave hyperthermia for breast cancer treatment  

Microsoft Academic Search

We present a computational study comparing the performance of narrowband (NB) microwave hyperthermia for breast cancer treatment with a recently proposed ultra-wideband (UWB) approach. Space-time beamforming is used to preprocess input signals from both UWB and NB sources. The train of UWB pulses or the NB sinusoidal signals are then transmitted simultaneously from multiple antennas into the breast. Performance is

Mark Converse; Essex J. Bond; Barry D. Van Veen; C. Hagness

2006-01-01

29

Ultra-wideband radar motion sensor  

DOEpatents

A motion sensor is based on ultra-wideband (UWB) radar. UWB radar range is determined by a pulse-echo interval. For motion detection, the sensors operate by staring at a fixed range and then sensing any change in the averaged radar reflectivity at that range. A sampling gate is opened at a fixed delay after the emission of a transmit pulse. The resultant sampling gate output is averaged over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion.

McEwan, Thomas E. (Livermore, CA)

1994-01-01

30

Ultra-wideband radar motion sensor  

DOEpatents

A motion sensor is based on ultra-wideband (UWB) radar. UWB radar range is determined by a pulse-echo interval. For motion detection, the sensors operate by staring at a fixed range and then sensing any change in the averaged radar reflectivity at that range. A sampling gate is opened at a fixed delay after the emission of a transmit pulse. The resultant sampling gate output is averaged over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion. 15 figs.

McEwan, T.E.

1994-11-01

31

Performance analysis of b-bit digital receivers for TR-UWB systems with inter-pulse interference  

Microsoft Academic Search

An ultra-wideband (UWB) transmitted reference (TR) system transmits an un-modulated pulse and a delayed modulated pulse pair. Then, a correlation receiver uses the former to demodulate the latter. Because of the long spread of a typical UWB channel, time delay between the two pulses is preferable to be larger than the channel delay spread for reduced noise at the receiver.

Jin Tang; Zhengyuan Xu; Brian M. Sadler

2007-01-01

32

4 Gbps impulse radio (IR) ultra-wideband (UWB) transmission over 100 meters multi mode fiber with 4 meters wireless transmission.  

PubMed

We present experimental demonstrations of in-building impulse radio (IR) ultra-wideband (UWB) link consisting of 100 m multi mode fiber (MMF) and 4 m wireless transmission at a record 4 Gbps, and a record 8 m wireless transmission at 2.5 Gbps. A directly modulated vertical cavity surface emitting laser (VCSEL) was used for the generation of the optical signal. 8 m at 2.5 Gbps corresponds to a bit rate--distance product of 20; the highest yet reported for wireless IR-UWB transmission. PMID:19770906

Jensen, Jesper Bevensee; Rodes, Roberto; Caballero, Antonio; Yu, Xianbin; Gibbon, Timothy Braidwood; Monroy, Idelfonso Tafur

2009-09-14

33

Digital receiver for TR-UWB systems with inter-pulse interference  

Microsoft Academic Search

An ultra wideband (UWB) transmitted reference (TR) system that allows inter-pulse interference (IPI) was recently proposed. It relaxes a restrictive requirement that the reference pulse has to be well separated from the data-modulated pulse as in a conventional TR system. With that scheme, data rate is substantially increased, especially in a long multipath channel, and better detection performance of the

Jilirr Tang; Zhengyuan Xu; Brian M. Sadler

2005-01-01

34

Data detection for UWB transmitted reference systems with inter-pulse interference  

Microsoft Academic Search

An ultra wideband (UWB) transmitted reference (TR) scheme transmits an un-modulated pulse and a delayed modulated pulse each time. Then a correlation receiver uses the former to demodulate the latter. However, to guarantee satisfactory detection performance in severe multipath distortion, two pulses have to be well separated by at least the channel spread, resulting in reduced data rate. In this

Zhengyuan Xu; Brian M. Sadler; Jin Tang

2005-01-01

35

Widely Tunable Ultra-Wideband Signals Generation Utilizing Optically Injected Semiconductor Laser  

Microsoft Academic Search

We propose and experimentally demonstrate an approach to generate ultra-wideband (UWB) pulse based on period-one oscillation of semiconductor laser. The baseband UWB signal with 10-dB bandwidth of 5.59 GHz is generated when the gain-switched pulse train is injected into the slave laser diode. Moreover, the center frequency of the generated UWB signal can be continuously tuned and converted up to

Yuncai Wang; Jianyu Zheng; Mingjiang Zhang; Anbang Wang

2011-01-01

36

Effect and Compensation of Colored Timing Jitter in Pulsed UWB Systems  

Microsoft Academic Search

Ultra-wideband (UWB) systems impose a stringent requirement on the jitter performance of the system clock. So far, only the effect of white Gaussian timing jitter has been considered in the literature via numerical simulation. However, practical clocks commonly exhibit colored jitter. In this paper, we first investigate the bit error rate (BER) performance of a single-user binary pulse position modulation

C. C. Ko; Lei Huang; Boon Hor Poh

2007-01-01

37

Integrated Distributed Transversal Filters for Pulse Shaping and Interference Suppression in UWB Impulse Radios  

Microsoft Academic Search

The stringent emission mask and interference specifications in ultra-wideband (UWB) impulse radios present great challenges for the transceiver architecture design and circuit implementation. This paper proposes to use integrated distributed transversal filters (DTF) for pulse shaping in the transmitter and for narrow-band interference (NBI) suppression in the receiver. Analyses show that an integrated DTF can accurately generate notches at multiple

Yunliang Zhu; Hui Wu

2006-01-01

38

Characterization of Ultra Wideband Multiple Access Performance Using Time Hopped-Biorthogonal Pulse Position Modulation.  

National Technical Information Service (NTIS)

The FCC's release of its UWB First Report and Order in April 2002 spawned renewed interest in impulse signaling research. This work combines Time Hopped (TH) multiple access coding with 4-ary UWB Biorthogonal Pulse Position Modulation (TH-BPPM). Multiple ...

D. J. Clabaugh

2004-01-01

39

Ultra-wideband source research  

Microsoft Academic Search

Ultra-wideband (UWB) microwave sources and antennas are of interest for a variety of applications such as transient radar, mine detection and unexploded ordnance (UXO) location and identification. Much of the current research is being performed at the Air Force Research Laboratory (AFRL) at Kirtland AFB, NM, USA. The approach to high power source development has included high pressure gas switching,

William D. Prather; Carl E. Baum; Jane M. Lehr; J. P. O'Loughlin; S. Tyo; J. S. H. Schoenberg; R. J. Torres; T. C. Tran; D. W. Scholfield; J. W. Burger; J. Gaudet

1999-01-01

40

Ultra-wideband characterization of obstructed propagation  

Microsoft Academic Search

Ultra-Wideband (UWB) signaling is finding many applications in through-wall imaging, target positioning, and indoor communications. In this context, signal propagation through walls has to be modeled accurately since the different building materials have varying attenuation and dispersion properties that impact UWB signal propagation. One of the interesting properties of a UWB signal is its ability to penetrate walls and obstacles

Nuruddeen Iya; Ali Muqaibel; Umar Johar; Mohamed Adnan Landolsi

2011-01-01

41

Ultra wideband L-loop antenna  

Microsoft Academic Search

The antenna design for ultra wideband (UWB) signal radiation is one of the main challenges of the UWB system, especially when low-cost, geometrically small and radio efficient structures are required for typical applications. This study presents a novel printed loop antenna with introducing an L shape portion to its arms. The antenna offers excellent performance for lower-band frequency of UWB

K. Y. Yazdanboost; R. Kohno

2005-01-01

42

Novel ultra-wideband (UWB) photonic generation through photodetection and cross-absorption modulation in a single electroabsorption modulator.  

PubMed

We propose and demonstrate, by proof of concept, a novel method of ultra-wide band (UWB) photonic generation using photodetection and cross-absorption modulation (XAM) of multiple quantum wells (MQW) in a single short-terminated electroabsorption modulator (SEAM). As an optical pump pulse excite the MQWs of SEAM waveguide, the probe light pulse with the same polarity can be generated through XAM, simultaneously creating photocurrent pulse propagating along the waveguide. Using the short termination of SEAM accompanied by the delayed microwave line, the photocurrent pulse can be reversed in polarity and re-modulated the waveguide, forming a monocycle UWB optical pulse. An 89 ps cycle of monocycle pulse with 114% fractional bandwidth is obtained, where the electrical power spectrum centered at 4 GHz of frequency ranges from 0.1 GHz to 8 GHz for -10 dB drops. Meanwhile, the generation processing is also confirmed by observing the same cycle of monocycle electrical pulse from the photodetection of SEAM. The whole optical processing is performed inside a compact semiconductor device, suggesting the optoelectronic integration template has a potential for the application of UWB photonic generation. PMID:20389347

Wu, Tsu-Hsiu; Wu, Jui-pin; Chiu, Yi-Jen

2010-02-15

43

A UWB pulse generation based on a phase modulator and programmable filter  

NASA Astrophysics Data System (ADS)

A simple scheme for the ultra-wideband (UWB) pulse generation based on a phase modulator and programmable filter is proposed and experimentally demonstrated. By locating the center wavelength of two tunable lasers at left and right linear slope of the filter, polarity-reversed monocycle pluses are generated. A section of single mode fiber is utilized to introduce proper time delay between the pair of UWB monocycle pulses. By switching the programmable filter between bandpass filter and notch filter, positive and negative doublet pulse can be obtained additionally. The generated UWB pulses are measured in both time and frequency domain.

Yang, Chengliang; Xia, Li; Fu, Songnian; Liu, Deming

2014-05-01

44

Coupled-slotline-hybrid sampling mixer integrated with step-recovery-diode pulse generator for UWB applications  

Microsoft Academic Search

A new compact low-cost sampling mixer with internal local strobe-pulse generator for (carrierless) ultra-wideband (UWB) applications, especially for sub-sampling of UWB video pulse signals, is presented along with detailed design information. The sampler employs a double-sided planar structure to facilitate interface with the strobe-pulse generator and the baseband circuit without using wire connections or air bridges, enabling hybrid microwave integrated-circuit

Jeongwoo Han; Cam Nguyen

2005-01-01

45

Time Domain Responses of Printed UWB Antennas  

Microsoft Academic Search

Ultra-wideband (UWB) technology deals with generating, transmitting and receiving short pulses of sub-nanosecond duration. Thus, the time domain response of an antenna for UWB applications is as important as the traditional frequency domain antenna parameters. This paper discusses the time domain responses of two types of printed UWB antennas. It is shown that a smaller antenna with a shorter distance

Yiqiong Shi; Sheel Aditya; C. L. Law

2005-01-01

46

Ultra-wideband sources and antennas  

Microsoft Academic Search

Ultra-Wideband (UWB) sources and antennas are of interest for a variety of potential applications that range from transient radar systems to communications systems. In this paper, we discuss the research issues and progress being made in gas, oil and solid state switching, UWB sources, and antennas

W. D. Prather; Forrest J. Agee; Carl E. Baum; Jane M Lehr; J. P. O'Loughlin; Jeffrey W. Burger; Jon S. H. Schoenberg; David W. Scholfield; Robert J. Torres; Jonathan P. Hull; John A. Gaudet

1998-01-01

47

Self Organization of Wireless Sensor Networks Using Ultra-Wideband Radios  

SciTech Connect

Ultra-wideband (UWB) technology has proven to be useful in short range, high data rate, robust, and low power communications. These features can make UWB systems ideal candidates for reliable data communications between nodes of a wireless sensor network (WSN). However, the low powered UWB pulses can be significantly degraded by channel noise, inter-node interference, and intentional jamming. In this paper we present a novel interference suppression technique for UWB based WSNs that promises self-organization in terms of power conservation, scalability, and channel estimation for the entire distributed network.

Nekoogar, F; Dowla, F; Spiridon, A

2004-07-19

48

Multi-pulse frequency shifted (MPFS) multiple access modulation for ultra wideband  

DOEpatents

The multi-pulse frequency shifted technique uses mutually orthogonal short duration pulses o transmit and receive information in a UWB multiuser communication system. The multiuser system uses the same pulse shape with different frequencies for the reference and data for each user. Different users have a different pulse shape (mutually orthogonal to each other) and different transmit and reference frequencies. At the receiver, the reference pulse is frequency shifted to match the data pulse and a correlation scheme followed by a hard decision block detects the data.

Nekoogar, Faranak (San Ramon, CA); Dowla, Farid U. (Castro Valley, CA)

2012-01-24

49

Ultra-wideband communications: an idea whose time has come  

Microsoft Academic Search

Ultra-wideband (UWB) radio is a fast emerging technology with many unique attractive features that promotes major advances in wireless communications, networking, radar, imaging, and positioning systems. Research in UWB is still in its infancy stages, offering limited resources in handling the challenges facing the UWB communications. Understanding the unique properties and challenges of UWB communications as well as its application

Liuqing Yang; G. B. Giannakis

2004-01-01

50

Obstacle avoidance and concealed target detection using the Army Research Lab ultra-wideband synchronous impulse reconstruction (UWB SIRE) forward imaging radar  

NASA Astrophysics Data System (ADS)

The U.S. Army Research Laboratory (ARL), as part of a mission and customer funded exploratory program, has developed a new low-frequency, ultra-wideband (UWB) synthetic aperture radar (SAR) for forward imaging to support the Army's vision of an autonomous navigation system for robotic ground vehicles. These unmanned vehicles, equipped with an array of imaging sensors, will be tasked to help detect man-made obstacles such as concealed targets, enemy minefields, and booby traps, as well as other natural obstacles such as ditches, and bodies of water. The ability of UWB radar technology to help detect concealed objects has been documented in the past and could provide an important obstacle avoidance capability for autonomous navigation systems, which would improve the speed and maneuverability of these vehicles and consequently increase the survivability of the U. S. forces on the battlefield. One of the primary features of the radar is the ability to collect and process data at combat pace in an affordable, compact, and lightweight package. To achieve this, the radar is based on the synchronous impulse reconstruction (SIRE) technique where several relatively slow and inexpensive analog-to-digital (A/D) converters are used to sample the wide bandwidth of the radar signals. We conducted an experiment this winter at Aberdeen Proving Ground (APG) to support the phenomenological studies of the backscatter from positive and negative obstacles for autonomous robotic vehicle navigation, as well as the detection of concealed targets of interest to the Army. In this paper, we briefly describe the UWB SIRE radar and the test setup in the experiment. We will also describe the signal processing and the forward imaging techniques used in the experiment. Finally, we will present imagery of man-made obstacles such as barriers, concertina wires, and mines.

Nguyen, Lam; Wong, David; Ressler, Marc; Koenig, Francois; Stanton, Brian; Smith, Gregory; Sichina, Jeffrey; Kappra, Karl

2007-05-01

51

Hemispheric ultra-wideband antenna.  

SciTech Connect

This report begins with a review of reduced size ultra-wideband (UWB) antennas and the peculiar problems that arise when building a UWB antenna. It then gives a description of a new type of UWB antenna that resolves these problems. This antenna, dubbed the hemispheric conical antenna, is similar to a conventional conical antenna in that it uses the same inverted conical conductor over a ground plane, but it also uses a hemispheric dielectric fill in between the conductive cone and the ground plane. The dielectric material creates a fundamentally new antenna which is reduced in size and much more rugged than a standard UWB conical antenna. The creation of finite-difference time domain (FDTD) software tools in spherical coordinates, as described in SAND2004-6577, enabled this technological advance.

Brocato, Robert Wesley

2006-04-01

52

Micro-Doppler processing for ultra-wideband radar data  

NASA Astrophysics Data System (ADS)

In this paper, we describe an operational pulse Doppler radar imaging system for indoor target localization and classification, and show how a target's micro-Doppler signature (?DS) can be processed when ultra-wideband (UWB) waveforms are employed. Unlike narrowband radars where time-frequency signal representations can be applied to reveal the target time-Doppler frequency signatures, the UWB system permits joint range-time-frequency representation (JRTFR). JRTFR outputs the data in a 3D domain representing range, frequency, and time, allowing both the ?DS and high range resolution (HRR) signatures to be observed. We delineate the relationship between the ?DS and the HRR signature, showing how they would form a complimentary joint feature for classification. We use real-data to demonstrate the effectiveness of the UWB pulse-Doppler radar, combined with nonstationary signal analyses, in gaining valuable insights into human positioning and motions.

Smith, Graeme E.; Ahmad, Fauzia; Amin, Moeness G.

2012-05-01

53

Time-Reversal Based Range Extension Technique for Ultra-Wideband (UWB) Sensors and Applications in Tactical Communications and Networking.  

National Technical Information Service (NTIS)

This report summarizes our recent UWB testbed development work with specific progresses in measurement of current system, 2 by 1 MISO system implementation and waveform optimization. The radio testbed is in evolution toward a wideband MIMO system. MISO ti...

N. T. Guo P. P. Zhang R. C. Qiu Y. Song Z. E. Hu

2009-01-01

54

Scalable UWB photonic generator based on the combination of doublet pulses.  

PubMed

We propose and experimentally demonstrate a scalable and reconfigurable optical scheme to generate high order UWB pulses. Firstly, various ultra wideband doublets are created through a process of phase-to-intensity conversion by means of a phase modulation and a dispersive media. In a second stage, doublets are combined in an optical processing unit that allows the reconfiguration of UWB high order pulses. Experimental results both in time and frequency domains are presented showing good performance related to the fractional bandwidth and spectral efficiency parameters. PMID:24977794

Moreno, Vanessa; Rius, Manuel; Mora, José; Muriel, Miguel A; Capmany, José

2014-06-30

55

Remote Monitoring and Tracking of UF6 Cylinders Using Long-Range Passive Ultra-wideband (UWB) RFID Tags  

SciTech Connect

An IAEA Technical Meeting on Techniques for IAEA Verification of Enrichment Activities identified 'smart tags' as a technology that should be assessed for tracking and locating UF6 cylinders. Although there is vast commercial industry working on RFID systems, the vulnerabilities of commercial products are only beginning to emerge. Most of the commercially off-the-shelf (COTS) RFID systems operate in very narrow frequency bands, making them vulnerable to detection, jamming and tampering and also presenting difficulties when used around metals (i.e. UF6 cylinders). Commercial passive RFID tags have short range, while active RFID tags that provide long ranges have limited lifetimes. There are also some concerns with the introduction of strong (narrowband) radio frequency signals around radioactive and nuclear materials. Considering the shortcomings of commercial RFID systems, in their current form, they do not offer a promising solution for continuous monitoring and tracking of UF6 cylinders. In this paper, we identify the key challenges faced by commercial RFID systems for monitoring UF6 cylinders, and introduce an ultra-wideband approach for tag/reader communications that addresses most of the identified challenges for IAEA safeguards applications.

Nekoogar, F; Dowla, F

2007-06-06

56

Ultra-wideband source and antenna research  

Microsoft Academic Search

Ultra-wideband (UWB) microwave sources and antennas are of interest for a variety of applications, such as transient radar, mine detection, and unexploded ordnance (UXO) location and identification. Much of the current research is being performed at the Air Force Research Laboratory (AFRL) at Kirtland AFB, NM. The approach to high power source development has included high pressure gas switching, oil

William D. Prather; Carl E. Baum; Jane M. Lehr; J. P. O'Loughlin; S. Tyo; J. S. H. Schoenberg; R. J. Torres; T. C. Tran; D. W. Scholfield; J. Gaudet; J. W. Burger

2000-01-01

57

Timing acquisition in ultra-wideband communication systems  

Microsoft Academic Search

The goal of this paper is to highlight the significance of the timing acquisition problem in ultra-wideband (UWB) communication systems and discuss efficient solutions to the problem. We discuss how the distinguishing features of UWB communication systems, such as their wide bandwidth and low transmission power constraints, are responsible for making the acquisition of UWB signals a difficult task. A

Sandeep R. Aedudodla; Saravanan Vijayakumaran; Tan F. Wong

2005-01-01

58

Ultra-Wideband Angle-of-Arrival Tracking Systems  

NASA Technical Reports Server (NTRS)

Systems that measure the angles of arrival of ultra-wideband (UWB) radio signals and perform triangulation by use of those angles in order to locate the sources of those signals are undergoing development. These systems were originally intended for use in tracking UWB-transmitter-equipped astronauts and mobile robots on the surfaces of remote planets during early stages of exploration, before satellite-based navigation systems become operational. On Earth, these systems could be adapted to such uses as tracking UWB-transmitter-equipped firefighters inside buildings or in outdoor wildfire areas obscured by smoke. The same characteristics that have made UWB radio advantageous for fine resolution ranging, covert communication, and ground-penetrating radar applications in military and law-enforcement settings also contribute to its attractiveness for the present tracking applications. In particular, the waveform shape and the short duration of UWB pulses make it possible to attain the high temporal resolution (of the order of picoseconds) needed to measure angles of arrival with sufficient precision, and the low power spectral density of UWB pulses enables UWB radio communication systems to operate in proximity to other radio communication systems with little or no perceptible mutual interference.

Arndt, G. Dickey; Ngo, Phong H.; Phan, Chau T.; Gross, Julia; Ni, Jianjun; Dusl, John

2010-01-01

59

Use of Ultra-Wideband (UWB) Technology for Designated Short Range Communications (DSRC) for Highway and High-Speed Rail ITS-IDEA Project 66.  

National Technical Information Service (NTIS)

MSSI has successfully completed the design and development of an Ultra Wideband (UBW) Electronic License Plate (ELP) that is capable of transmitting driver and vehicle information for Designated Short Range Communication (DSRC) applications. The ELP is al...

R. Fontana

2001-01-01

60

Optimal Waveforms Design for Ultra-Wideband Impulse Radio Sensors  

PubMed Central

Ultra-wideband impulse radio (UWB-IR) sensors should comply entirely with the regulatory spectral limits for elegant coexistence. Under this premise, it is desirable for UWB pulses to improve frequency utilization to guarantee the transmission reliability. Meanwhile, orthogonal waveform division multiple-access (WDMA) is significant to mitigate mutual interferences in UWB sensor networks. Motivated by the considerations, we suggest in this paper a low complexity pulse forming technique, and its efficient implementation on DSP is investigated. The UWB pulse is derived preliminarily with the objective of minimizing the mean square error (MSE) between designed power spectrum density (PSD) and the emission mask. Subsequently, this pulse is iteratively modified until its PSD completely conforms to spectral constraints. The orthogonal restriction is then analyzed and different algorithms have been presented. Simulation demonstrates that our technique can produce UWB waveforms with frequency utilization far surpassing the other existing signals under arbitrary spectral mask conditions. Compared to other orthogonality design schemes, the designed pulses can maintain mutual orthogonality without any penalty on frequency utilization, and hence, are much superior in a WDMA network, especially with synchronization deviations.

Li, Bin; Zhou, Zheng; Zou, Weixia; Li, Dejian; Zhao, Chong

2010-01-01

61

Study of UWB time-domain antenna array scan  

Microsoft Academic Search

Ultra wideband (UWB) antenna is widely used in UWB communication, radar and electronic warfare in recent years. UWB antenna is indispensable in impulse radar, which transmits and receives short electromagnetic pulse signals, and preserves the waveform well. To detect and track moving-target, UWB time-domain antenna array is studied in this paper. Firstly, the theory of time-domain antenna array scan is

Yuan Xue-Lin; Zhang Guang-Fu; Huang Jin-Jian; Yuan Nai-Chang

2008-01-01

62

Waveform Analysis of UWB GPR Antennas  

Microsoft Academic Search

Ground Penetrating Radar (GPR) systems fall into the category of ultra- wideband (UWB) devices. Most GPR equipment covers a frequency range between an octave and a decade by using short-time pulses. Each signal recorded by a GPR gathers a temporal log of attenuated and distorted versions of these pulses (due to the effect of the propagation medium) plus possible electromagnetic

Fernando I. Rial; Henrique Lorenzo; Manuel Pereira; Julia Armesto

2009-01-01

63

Issues in ultra-wideband, widebeam SAR image formation  

Microsoft Academic Search

The formation of low-frequency, ultra-wideband\\/widebeam (UWB\\/WB) SAR imagery faces inherent challenges not present in conventional SAR systems operating at higher frequencies. Small angle approximations and other shortcuts taken in conventional SAR processors may be inappropriate for the UWB\\/WB SAR processor. The severe range migration associated with fine resolution UWB\\/WB SAR poses a significant problem for the image formation algorithm. The

Ron Goodman; Sreenidhi Tummala; Walter Carrara

1995-01-01

64

Design of a CPW-fed Ultra Wideband Crown Circular Fractal Antenna  

Microsoft Academic Search

A new ultra wideband antenna fed by coplanar waveguide (CPW) is presented in this paper. A fractal structure is constructed to obtain ultra wideband (UWB) performance. The parameters and characteristics of the antenna and the simulation results show that the 6:1 or more bandwidth is achieved with the second order iterative antenna structure

Min Ding; Ronghong Jin; Junping Geng; Qi Wu; Wei Wang

2006-01-01

65

Cyclic Prefix Signaling for Pulse Shape Modulation UWB RAKE Receivers  

NASA Astrophysics Data System (ADS)

Combining transmission of ultra wideband pulses, organized in blocks, with the inclusion of cyclic prefixing pulses yields a pulsewidth periodic signal at the receiver. Although unknown, this signal fits perfectly the diversity exploitive architecture of a RAKE receiver. Aiming to profit from this signal arrangement, we propose a pulse shape modulation system employing a RAKE receiver that estimates this periodic signal during a training interval and uses the estimated values for detection of data symbols. Our proposal relies on the invariability of the multipath propagation channel during the transmission of a UWB packet, the adequate application of the cyclic prefix, and the fact that different transmitted pulses result in different periodic signals at the receiver. This system is equivalent to transforming the multipath nature of the UWB propagation channel into a multichannel digital communications affected solely by additive noise. Our proposal is important because it ameliorates the performance of a pulse shape modulation RAKE receiver. On the other hand, the cost of our proposed system resides in the inefficiencies product of the cyclic prefix inclusion.

Cartagena Gordillo, Alex; Kohno, Ryuji

66

Short range automotive radar based on UWB pseudo-random coding  

Microsoft Academic Search

In this paper, a radar system for short range automotive application based on ultra-wideband (UWB) technology is studied. UWB uses very short pulses, so that the spectrum of the transmitted signals may spread over several Gigahertzes. In order to increase, from one part, the resolution in distance of this radar system and to avoid, from another part, multi-users interferences for

L. Sakkila; Y. Elhillali; A. Rivenq; C. Tatkeu; J.-M. Rouvaen

2007-01-01

67

Performance of a 60GHz DCM-OFDM and BPSK-Impulse Ultra-Wideband System with Radio-Over-Fiber and Wireless Transmission Employing a Directly-Modulated VCSEL  

Microsoft Academic Search

The performance of radio-over-fiber optical trans- mission employing vertical-cavity surface-emitting lasers (VC- SELs), and further wireless transmission, of the two major ultra-wideband (UWB) implementations is reported when op- erating in the 60-GHz radio band. Performance is evaluated at 1.44 Gbit\\/s bitrate. The two UWB implementations considered employ dual-carrier modulation orthogonal frequency-division multiplexing (DCM-OFDM) and binary phase-shift keying im- pulse radio

Marta Beltran; Jesper Bevensee Jensen; Xianbin Yu; Roberto Llorente; Roberto Rodes; Markus Ortsiefer; Christian Neumeyr; Idelfonso Tafur Monroy

2011-01-01

68

Cross-layer functionality in ultra-wideband applications, The EUWB perspective  

Microsoft Academic Search

EUWB (Coexisting Short Range Radio by Advanced Ultra-Wideband Radio Technology, FP7-ICT-215669, www.euwb.eu) has been an industry-led initiative of twenty-one major industrial and excellent academic organizations from Europe and Israel targeting innovative improvement, adaptation, integration and application of short-range Ultra-Wideband Radio Technology (UWB-RT). EUWB will effectively leverage and significantly enhance the scientific knowledge base in the advanced UWB-RT and will provide

Christian KOCKS; Alexander VIESSMANN; Shangbo Wang; Ernest SCHEIBER; Dong Xu; Guido H. BRUCK; Peter JUNG; S. Zeisberg

2009-01-01

69

An Evaluation of Ultra Wideband Technology for Indoor Ranging  

Microsoft Academic Search

Ultra wideband technology shows promise for precision ranging due to its fine time resolution to resolve multipath fading and the presence of lower frequencies in the baseband to penetrate walls. While a concerted effort has been conducted in the extensive modeling of the indoor UWB channel in recent years, to our knowledge only two papers have reported ranging performance, but

Camillo Gentile; Alfred Kik

2006-01-01

70

Augmented Reality Using Ultra-Wideband Radar Imagery.  

National Technical Information Service (NTIS)

The U.S. Army Research Laboratory (ARL) has been investigating the utility of ultra-wideband (UWB) synthetic aperture radar (SAR) technology for detecting concealed targets in various applications. We have designed and built a vehicle-based, low-frequency...

F. Koenig K. Sherbondy L. Nguyen

2010-01-01

71

Evaluation of an Ultra-Wideband Propagation Channel  

Microsoft Academic Search

This paper describes the results of an ultra- wideband (UWB) propagation study in which arrays of propagation measurements were made. After a description of the propagation measurement technique, an approach to the spatial and temporal decomposition of an array of mea- surements into wavefronts impinging on the receiving array is presented. Based on am odification of the CLEAN algo- rithm,

J. M. Cramer; R. A. Scholtz; M. Z. Win

2002-01-01

72

Time-domain imaging of radar targets using ultra-wideband or short pulse radars  

Microsoft Academic Search

The development of viable short-pulse radar system has renewed the interest in time domain imaging performed directly in time-domain with temporally measured signal. Since the short-pulse response of a target provides significant information about the positions and strengths of scattering centers, and if observations are made over a wide range of aspect angle, one might create an image of the

Yingcheng Dai

1997-01-01

73

A novel synchronization algorithm in ultra-wideband system  

Microsoft Academic Search

Synchronization remains one of the biggest challenges in the ultra-wideband (UWB) impulse radio system. In this paper, a frame-level synchronization algorithm is proposed in differential transmitted reference (DTR) UWB systems in the multipath environment. The signal structure is judiciously designed with the aided data and m-sequence code. Enjoying the fine property of m-sequence autocorrelation function, the proposed algorithm can suppress

Biao Liu; Tiejun Lv; Yongwei Qiao; Weidong Liu; Long Gao

2009-01-01

74

Planar elliptical element ultra-wideband dipole antennas  

Microsoft Academic Search

Abstract: This note introduces a new class of ,planar ultra-wideband (UWB) dipoles that use elliptical elements. These ,antennas offer good ,dipole performance ,over nearly two octaves in frequency. Unlike ,more traditional broadband dipole elements that must be around a quarter-wavelength to radiate efficiently, planar elliptical UWB dipoles still exhibit a –10 dB return loss for a 0.20? element size, and

H. G. Schantz

2002-01-01

75

Daredevil: ultra-wideband radar sensing for small UGVs  

Microsoft Academic Search

We are developing an ultra wideband (UWB) radar sensor payload for the man-portable iRobot PackBot UGV. Our goal is to develop a sensor array that will allow the PackBot to navigate autonomously through foliage (such as tall grass) while avoiding obstacles and building a map of the terrain. We plan to use UWB radars in conjunction with other sensors such

Brian Yamauchi

2007-01-01

76

On the UWB system coexistence with GSM900, UMTS\\/WCDMA, and GPS  

Microsoft Academic Search

This paper evaluates the level of interference caused by different ultra-wideband (UWB) signals to other various radio systems, as well as the performance degradation of UWB systems in the presence of narrowband interference and pulsed jamming. The in-band interference caused by a selection of UWB signals is calculated at GSM900, UMTS\\/wideband code-division multiple-access (WCDMA), and Global Position System (GPS) frequency

Matti Hämäläinen; Veikko Hovinen; Raffaello Tesi; Jari H. J. Iinatti; Matti Latva-aho

2002-01-01

77

Ultra-wideband radios for time-of-flight-ranging and network position estimation  

DOEpatents

This invention provides a novel high-accuracy indoor ranging device that uses ultra-wideband (UWB) RF pulsing with low-power and low-cost electronics. A unique of the present invention is that it exploits multiple measurements in time and space for very accurate ranging. The wideband radio signals utilized herein are particularly suited to ranging in harsh RF environments because they allow signal reconstruction in spite of multipath propagation distortion. Furthermore, the ranging and positioning techniques discussed herein directly address many of the known technical challenges encountered in UWB localization regarding synchronization and sampling. In the method developed, noisy, corrupted signals can be recovered by repeating range measurements across a channel, and the distance measurements are combined from many locations surrounding the target in a way that minimizes the range biases associated to indirect flight paths and through-wall propagation delays.

Hertzog, Claudia A. (Houston, TX); Dowla, Farid U. (Castro Valley, CA); Dallum, Gregory E. (Livermore, CA); Romero, Carlos E. (Livermore, CA)

2011-06-14

78

On the performance of UWB and DS-spread spectrum communication systems  

Microsoft Academic Search

We consider a binary spread spectrum system, with possibly episodic transmission; i.e., the system transmits n pulses per information bit, and allows for off time separation between pulses. Processing gain enables low power transmission, and the ultra wideband (UWB) spreading limits the interference effects into narrowband systems. We consider the issues of processing gain, jamming margin, coding gain and multiuser

B. M. Sadler; Anunthrum Swami

2002-01-01

79

Compact band-notched ultra wideband printed monopole antenna  

Microsoft Academic Search

A simple and compact microstrip-fed ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed in this paper. The antenna is composed of a cirque ring with a small strip bar, so that the antenna occupies about 8.29 GHz bandwidth covering 3.18-11.47 GHz with expected band rejection of 5.09 GHz to 5.88 GHz. A quasi-omnidirectional and quasi-symmetrical radiation pattern

Jing Jiao; Hong-wei Deng; Yong-jiu Zhao

2008-01-01

80

FDTD simulation tools for UWB antenna analysis.  

SciTech Connect

This paper describes the development of a set of software tools useful for analyzing ultra-wideband (UWB) antennas and structures. These tools are used to perform finite difference time domain (FDTD) simulation of a conical antenna with continuous wave (CW) and UWB pulsed excitations. The antenna is analyzed using spherical coordinate-based FDTD equations that are derived from first principles. The simulation results for CW excitation are compared to simulation and measured results from published sources; the results for UWB excitation are new.

Brocato, Robert Wesley

2004-12-01

81

FDTD simulation tools for UWB antenna analysis.  

SciTech Connect

This paper describes the development of a set of software tools useful for analyzing ultra-wideband (UWB) antennas and structures. These tools are used to perform finite difference time domain (FDTD) simulation of a conical antenna with continuous wave (CW) and UWB pulsed excitations. The antenna is analyzed using spherical coordinate-based FDTD equations that are derived from first principles. The simulation results for CW excitation are compared to simulation and measured results from published sources; the results for UWB excitation are new.

Brocato, Robert Wesley

2005-02-01

82

UWB Free-Space Characterization and Shape Recognition of Dielectric Objects Using Statistical Methods  

Microsoft Academic Search

This paper presents a novel method for the free-space characterization and shape recognition of dielectric objects using multivariate calibration methods and linear discriminant analysis. The dimensions of the variously shaped objects are comparable with some of the transmitted wavelengths of the ultra-wideband (UWB) time-domain pulses used. A system illuminating the objects under test by a subnanosecond UWB pulse has been

Henning Mextorf; Frank Daschner; Mike Kent; Reinhard H. Knöchel

2011-01-01

83

An efficient synchronization scheme for digital UWB communication systems for biomedical applications  

Microsoft Academic Search

Wireless biomedical applications require low power operations for long, uninterrupted durations of use. In order to harness the low power characteristics of Ultra Wideband (UWB) systems, issues involving the synchronization of extremely short pulses have to be resolved as they surface as major bottlenecks of the design of such systems. The situation is particularly adverse in short range communication systems

Muhammad Cassim Munshi; Jinhua Jiang; Yan Xin; Tor Sverre Lande; Yong Lian

2008-01-01

84

Compact Ultra-Wideband Antenna for Portable Devices  

NASA Astrophysics Data System (ADS)

This article presents a compact ultra-wideband (UWB) antenna for wireless dongle devices. The printed monopole antenna, with the size of 15 mm × 30 mm, has an impedance bandwidth ranges from 2.9 to 13 GHz. The proposed structure comprises of a hexagonal radiator fed by a microstrip line with a modified ground plane. Such a design can be easily integrated with wireless universal serial bus (USB) devices. Having stable radiation patterns and constant gain within the UWB spectrum are significant characteristics of this antenna. The time domain studies on the designed antenna indicate reduced ringing effect for impulse excitation across the band of interest.

Kasi, B.; Ping, L. C.; Chakrabarty, C. K.

2013-06-01

85

Daredevil: ultra-wideband radar sensing for small UGVs  

NASA Astrophysics Data System (ADS)

We are developing an ultra wideband (UWB) radar sensor payload for the man-portable iRobot PackBot UGV. Our goal is to develop a sensor array that will allow the PackBot to navigate autonomously through foliage (such as tall grass) while avoiding obstacles and building a map of the terrain. We plan to use UWB radars in conjunction with other sensors such as LIDAR and vision. We propose an algorithm for using polarimetric (dual-polarization) radar arrays to classify radar returns as either vertically-aligned foliage or solid objects based on their differential reflectivity, a function of their aspect ratio. We have conducted preliminary experiments to measure the ability of UWB radars to detect solid objects through foliage. Our initial results indicate that UWB radars are very effective at penetrating sparse foliage, but less effective at penetrating dense foliage.

Yamauchi, Brian

2007-05-01

86

UWB pulse propagation into human tissues  

NASA Astrophysics Data System (ADS)

In this paper the propagation of a UWB pulse into a layered model of the human body is studied to characterize absorption and reflection of the UWB signal due to the different body tissues. Several time behaviours for the incident UWB pulse are considered and compared with reference to the feasibility of breath and heartbeat activity monitoring. Results show that if the UWB source is placed far from the human body, the reflection coming from the interface between air and skin can be used to detect the respiratory activity. On the contrary, if the UWB source is placed close to the human body, a small reflection due to the interface between the posterior lung wall and the bone, which is well distanced in time from the reflections due to the first layers of the body model, can be used to detect lung and heart changes associated with the cardio-respiratory activity.

Cavagnaro, Marta; Pittella, Erika; Pisa, Stefano

2013-12-01

87

Ultra wideband microwave system with novel image reconstruction strategies for breast cancer detection  

Microsoft Academic Search

The paper reports the design of an ultra wideband (UWB) microwave imaging system for breast cancer detection. The system uses a circular array formed by twelve UWB Tapered Slot Antennas (TSAs) operating over a 3.0-11.0GHz band which are connected to a Vector Network Analyser (VNA) with two single-pole multiple-through microwave coaxial switches. Using this electronic switching network with an additional

Marek E. Bialkowski

2010-01-01

88

Ultra-Wideband Technology for Short or Medium-Range Wireless Communications  

Microsoft Academic Search

Ultra-Wideband (UWB) technology is loosely defined as any wireless transmission scheme that occupies a bandwidth of more than 25% of a center frequency, or more than 1.5GHz. The Federal Communications Commission (FCC) is currently working on setting emissions limits that would allow UWB communication systems to be deployed on an unlicensed basis following the Part 15.209 rules for radiated emissions

Jeff Foerster; Evan Green; Srinivasa Somayazulu; David Leeper

2001-01-01

89

A Vehicular Ultra-Wideband Channel Model for Future Wireless IntraVehicle Communications (IVC) Systems  

Microsoft Academic Search

Future wireless intra-vehicle communications (IVC) systems adopting ultra-wideband (UWB) radio are proposed in this paper, which provide onboard passengers with high-speed duplex data exchange services. In this paper, a vehicular UWB channel model is first developed by modifying the IEEE 802.15.3a indoor model to fit into the vehicular environments with dense and concentrated clusters and rays. The main channel statistical

Weidong Xiang

2007-01-01

90

Planar antennas in LTCC technology with transceiver integration capability for ultra-wideband applications  

Microsoft Academic Search

We present two novel ultra-wideband (UWB) antennas embedded in a low-temperature co-fired ceramic (LTCC) package designed to house the UWB transceiver chip. Given their planar topology, circuit integration possibilities, and compact size, a partial ground-plane triangular monopole antenna (PGP-TM) and an antipodal Vivaldi antenna (AVA) are fully characterized. The performance in both the frequency and time domain are presented. The

Grzegorz Brzezina; Langis Roy; Leonard MacEachern

2006-01-01

91

High power microwave generation with pulse compression  

Microsoft Academic Search

Chirped pulse compression is achieved in transmit modes with wideband antennas, such as log periodic dipole arrays (LPDA), where the matched filters are the antennas. In this paper, a modulation technique is described which compresses ultra wideband (UWB) signals on conventional LPDAs. In transmit modes, high power microwaves (HPM) applications are found with wideband transmitting antennas, such as LPDA, where

A. W. Biggs

1995-01-01

92

Ultra-Wideband Tracking System Design for Relative Navigation  

NASA Technical Reports Server (NTRS)

This presentation briefly discusses a design effort for a prototype ultra-wideband (UWB) time-difference-of-arrival (TDOA) tracking system that is currently under development at NASA Johnson Space Center (JSC). The system is being designed for use in localization and navigation of a rover in a GPS deprived environment for surface missions. In one application enabled by the UWB tracking, a robotic vehicle carrying equipments can autonomously follow a crewed rover from work site to work site such that resources can be carried from one landing mission to the next thereby saving up-mass. The UWB Systems Group at JSC has developed a UWB TDOA High Resolution Proximity Tracking System which can achieve sub-inch tracking accuracy of a target within the radius of the tracking baseline [1]. By extending the tracking capability beyond the radius of the tracking baseline, a tracking system is being designed to enable relative navigation between two vehicles for surface missions. A prototype UWB TDOA tracking system has been designed, implemented, tested, and proven feasible for relative navigation of robotic vehicles. Future work includes testing the system with the application code to increase the tracking update rate and evaluating the linear tracking baseline to improve the flexibility of antenna mounting on the following vehicle.

Ni, Jianjun David; Arndt, Dickey; Bgo, Phong; Dekome, Kent; Dusl, John

2011-01-01

93

Induced Mitogenic Activity in AML-12 Mouse Hepatocytes Exposed to Low-dose Ultra-Wideband Electromagnetic Radiation  

PubMed Central

Ultra–wideband (UWB) technology has increased with the use of various civilian and military applications. In the present study, we hypothesized that low-dose UWB electromagnetic radiation (UWBR) could elicit a mitogenic effect in AML-12 mouse hepatocytes, in vitro. To test this hypothesis, we exposed AML-12 mouse hepatocytes, to UWBR in a specially constructed gigahertz transverse electromagnetic mode (GTEM) cell. Cells were exposed to UWBR for 2 h at a temperature of 23°C, a pulse width of 10 ns, a repetition rate of 1 kHz, and field strength of 5–20 kV/m. UWB pulses were triggered by an external pulse generator for UWBR exposure but were not triggered for the sham exposure. We performed an MTT Assay to assess cell viability for UWBR-treated and sham-exposed hepatocytes. Data from viability studies indicated a time-related increase in hepatocytes at time intervals from 8–24 h post exposure. UWBR exerted a statistically significant (p < 0.05) dose-dependent response in cell viability in both serum-treated and serum free medium (SFM) -treated hepatocytes. Western blot analysis of hepatocyte lysates demonstrated that cyclin A protein was induced in hepatocytes, suggesting that increased MTT activity after UWBR exposure was due to cell proliferation. This study indicates that UWBR has a mitogenic effect on AML-12 mouse hepatocytes and implicates a possible role for UWBR in hepatocarcinoma.

Dorsey, W. C.; Ford, B. D.; Roane, L.; Haynie, D. T.; Tchounwou, P. B.

2005-01-01

94

Power-efficient UWB generation based on hybrid of optical fiber link and RF circuits  

NASA Astrophysics Data System (ADS)

We propose a low cost solution to generate power efficient ultra-wideband (UWB) radio frequency (RF) signal based on the hybrid of optical fiber and RF circuits. In our solution, any return-to-zero (RZ) optical pulse with enough bandwidth is transmitted over optical fiber first, then converted to a power-efficient UWB pulse by an electrical bandpass filter (EBPF) with a passband of 3.1-10.6 GHz. The transmission and modulation of UWB signal is processed in optical domain, whereas the generation of UWB is processed in electrical domain. This solution embodies the advantages of both low-loss long-haul transmission of optical fiber and low-cost mature RF circuits. Both UWB modulations of on-off keying (OOK) and binary phase shift keying (BPSK) are experimentally demonstrated. The impacts of RZ pulsewidth and the EBPF bandwidth on the UWB waveforms are also discussed.

Dong, Jianji; Yu, Yu; Huang, Dexiu; Zhang, Xinliang

2012-12-01

95

Ultra-wideband 4 × 4 Phased Array Containing Exponentially Tapered Slot Antennas and a True-Time Delay Phase Shifter at UHF  

NASA Astrophysics Data System (ADS)

For angular scanning a true-time array is developed for UHF ultra-wideband (UWB) applications in time and/or frequency domain. It is based on a 4 × 4 array with antipodal exponentially tapered slot antennas (ETSA, Vivaldi) and a 3-bit phase shifter. Distances of antenna elements are designed to be compromise between gain, scanning angle, side/grating lobe levels. The uniform spaced and fed array maximizes the overall gain. After defining the antenna shape, corrugations are introduced to improve antenna matching and gain pattern. Nine equally spaced beam positions for a 90° scanning angle are induced by an optimized 3-bit phase shifter on high permittivity substrate, while 4 bits are usually needed. Parasitic resonances are avoided by using PIN diodes in single pole double throw configuration. All components and the complete array system are simulated and verified in frequency domain with good agreement. Adaptation to UWB pulses is possible.

Schmitz, J.; Jung, M.; Bonney, J.; Caspary, R.; Schüür, J.; Schöbel, J.

96

Survey of Ultra-wideband Radar  

NASA Astrophysics Data System (ADS)

The development of UWB radar over the last four decades is very briefly summarized. A discussion of the meaning of UWB is followed by a short history of UWB radar developments and discussions of key supporting technologies and current UWB radars. Selected UWB radars and the associated applications are highlighted. Applications include detecting and imaging buried mines, detecting and mapping underground utilities, detecting and imaging objects obscured by foliage, through-wall detection in urban areas, short-range detection of suicide bombs, and the characterization of the impulse responses of various artificial and naturally occurring scattering objects. In particular, the Naval Research Laboratory's experimental, low-power, dual-polarized, short-pulse, ultra-high resolution radar is used to discuss applications and issues of UWB radar. Some crucial issues that are problematic to UWB radar are spectral availability, electromagnetic interference and compatibility, difficulties with waveform control/shaping, hardware limitations in the transmission chain, and the unreliability of high-power sources for sustained use above 2 GHz.

Mokole, Eric L.; Hansen, Pete

97

A Comprehensive Evaluation of Joint Range and Angle Estimation in Ultra-Wideband Location Systems for Indoors  

Microsoft Academic Search

Fine time resolution enables Ultra-Wideband (UWB) ranging systems to reliably extract the first multipath arrival corresponding to the range between a transmitter and receiver, even when attenuated in strength compared to later arrivals. Bearing systems alone lack any notion of time and in general select the arrival coinciding with the strongest path, which is rarely the first one in non

Camillo Gentile; A. Judson Braga; Alfred Kik

2008-01-01

98

Design of Spectrally Efficient Hermite Pulses for PSM UWB Communications  

NASA Astrophysics Data System (ADS)

In this paper, we propose a method for designing a set of pulses whose spectrum is efficiently contained in amplitude and bandwidth. Because these pulses are derived from and have shapes that are either equal or similar to the Hermite pulses, we name our proposed transmit pulses as spectrally efficient Hermite pulses. Given that the proposed set of pulses does not constitute an orthonormal one, we also propose a set of receive templates which permit orthonormal detection of the incoming signals at the receiver. The importance of our proposal is in the potential implementation of M-ary pulse shape modulation systems, for ultra wideband communications, with sets of pulses that are efficiently contained within a specific bandwidth and limited to a certain amplitude.

Gordillo, Alex Cartagena; Kohno, Ryuji

99

FMCW ultra-wideband radar for through-the- wall detection of human beings  

Microsoft Academic Search

An FMCW ultra-wideband radar concept for through-the-wall detection of human beings is presented. Propagation modeling through different types of walls and radar cross section measurements of human beings are given. Power budget and dynamic range are computed and discussed for different situations. The realized UWB FM-CW radar is presented and some fast trials of human beings tracking are shown. This

Nadia Maaref; Patrick Millot; Christian Pichot; Odile Picon

2009-01-01

100

Permittivity-matched compact ceramic ultra-wideband horn antennas for biomedical diagnostics  

Microsoft Academic Search

Ultra-wideband (UWB) biomedical radar systems are an important means for the diagnostic inspection and monitoring of physiological signatures. Geometrically small antennas and high-resolution imaging techniques are required for such appli- cations. We have analysed the time-domain reflection and trans- mission characteristics of compact ceramic double-ridged horn antennas, developed for contact-mode measurements with a permittivity matched to human tissues. Preliminary volunteer

F. Scotto di Clemente; M. Helbig; J. Sachs; U. Schwarz; R. Stephan; M. A. Hein

2011-01-01

101

Experimental Analysis of 60GHz VCSEL and ECL Photonic Generation and Transmission of Impulse-Radio Ultra-Wideband Signals  

Microsoft Academic Search

Optical generation of impulse-radio ultra-wideband (UWB) signals in the 60-GHz band is proposed and experimentally demonstrated. External-cavity laser (ECL) and vertical-cavity surface-emitting laser (VCSEL) is employed for frequency up-conversion by heterodyne mixing with a UWB optical signal for comparison purposes. Real-time bit-error-rate (BER) perfor- mance of generated signals at 3.125 Gb\\/s is evaluated combining fiber and 2-m wireless transmission. Different

Marta Beltran; Jesper Bevensee Jensen; Roberto Llorente; Idelfonso Tafur Monroy

2011-01-01

102

Investigation of High-Accuracy Indoor 3-D Positioning Using UWB Technology  

Microsoft Academic Search

There are many challenges in building an ultra-wideband (UWB) indoor local positioning system for high-accuracy applications. These challenges include reduced accuracy due to multipath interference, sampling rate limitations, tag synchronization, and antenna phase-center variation. Each of these factors must be addressed to achieve millimeter or sub-millimeter accuracy. The developed system architecture is presented where a 300-ps Gaussian pulse modulates an

Mohamed R. Mahfouz; Cemin Zhang; Brandon C. Merkl; Michael J. Kuhn; Aly E. Fathy

2008-01-01

103

UWB Impulse Radio Transmitter Using an Electrooptic Phase Modulator Together With a Delay Interferometer  

Microsoft Academic Search

A simple ultra-wideband (UWB) impulse radio transmitter is experimentally demonstrated using an electrooptic phase modulator (PM) and a delay interferometer (DI). By applying an electrical nonreturn-to-zero (NRZ) baseband signal to the PM, a pair of optical Gaussian pulses with opposite polarities is generated at the two output ports of the DI. By properly setting the delay between these two polarity-reversed

Fangzheng Zhang; Songnian Fu; Jian Wu; Nam Quoc Ngo; Kun Xu; Yan Li; Xiaobin Hong; Ping Shum; Jintong Lin

2010-01-01

104

Compact electromagnetic bandgap structures for notch band in ultra-wideband applications.  

PubMed

This paper introduces a novel approach to create notch band filters in the front-end of ultra-wideband (UWB) communication systems based on electromagnetic bandgap (EBG) structures. The concept presented here can be implemented in any structure that has a microstrip in its configuration. The EBG structure is first analyzed using a full wave electromagnetic solver and then optimized to work at WLAN band (5.15-5.825 GHz). Two UWB passband filters are used to demonstrate the applicability and effectiveness of the novel EBG notch band feature. Simulation results are provided for two cases studied. PMID:22163430

Rotaru, Mihai; Sykulski, Jan

2010-01-01

105

Method of remote powering and detecting multiple UWB passive tags in an RFID system  

DOEpatents

A new Radio Frequency Identification (RFID), tracking, powering apparatus/system and method using coded Ultra-wideband (UWB) signaling is introduced. The proposed hardware and techniques disclosed herein utilize a plurality of passive UWB transponders in a field of an RFID-radar system. The radar system itself enables multiple passive tags to be remotely powered (activated) at about the same time frame via predetermined frequency UWB pulsed formats. Once such tags are in an activated state, an UWB radar transmits specific "interrogating codes" to put predetermined tags in an awakened status. Such predetermined tags can then communicate by a unique "response code" so as to be detected by an UWB system using radar methods.

Dowla, Farid U. (Castro Valley, CA); Nekoogar, Faranak (San Ramon, CA); Benzel, David M. (Livermore, CA); Dallum, Gregory E. (Livermore, CA); Spiridon, Alex (Palo Alto, CA)

2012-05-29

106

Non-invasive respiration rate estimation using ultra-wideband distributed cognitive radar system.  

PubMed

It has been shown that remote monitoring of pulmonary activity can be achieved using ultra-wideband (UWB) systems, which shows promise in home healthcare, rescue, and security applications. In this paper, a geometry-based statistical channel model is developed for simulating the reception of UWB signals in the indoor propagation environment. This model enables replication of time-varying multipath profiles due to the displacement of a human chest. Subsequently, a UWB distributed cognitive radar system (UWB-DCRS) is developed for the robust detection of chest cavity motion and the accurate estimation of respiration rate. The analytical framework can serve as a basis in the planning and evaluation of future measurement programs. PMID:17945609

Chen, Yifan; Gunawan, Erry; Low, Kay Soon; Kim, Yongmin; Soh, Cheong Boon; Leyman, A Rahim; Thi, Lin Lin

2006-01-01

107

Ultra-wideband for navigation and communications  

Microsoft Academic Search

Precision coordinated maneuvering of multiple space vehicles would offer significant performance advantages to both commercial and scientific missions by increasing the versatility and potential capabilities of the formation. Ultra-wideband systems can provide centimeter level accuracy ranging measurements over distances of kilometers, using only milliwatts of power from an omni-directional transceiver no bigger than a pager. Using these precise range measurements

J. C. Adams; W. Gregorwich; L. Capots; D. Liccardo

2001-01-01

108

Ultra wideband assessment of locomotion in elderly  

Microsoft Academic Search

Approximately 30 psychiatric syndromes including dementia and geriatric depression have disordered movement as a diagnostic sign. Moreover, changes in locomotor patterns result from pharmacological and behavioral interventions. Using ultra-wideband technology we are developing a system for real-time monitoring of the direction, duration and acceleration of movements by multiple residents in nursing home and assisted living environments. The long term goal

William D. Kearns; James L. Fozard

2008-01-01

109

Spectrum Shaping and NBI Suppression in UWB Communications  

Microsoft Academic Search

This paper investigates spectrum shaping in ultra-wideband (UWB) communications in order to introduce spectral nulls to limit interference with narrowband signals. Each transmitted symbol is represented by a \\

Yue Wang; Xiaodai Dong; Ivan J. Fair

2007-01-01

110

Ultra-wideband miniaturized microstrip patch antennas for wireless communications: Design guidelines and modeling  

NASA Astrophysics Data System (ADS)

The number of wireless communication applications continue to increase steadily, leading to competition for currently allocated frequency bands. Capacity issues in form of data rate and latency have always been a bottleneck for broadband wireless-communication usage. New communication systems like ultra-wideband (UWB) require larger bandwidth than what is normally utilized with traditional antenna techniques. The interest for compact consumer electronics is growing in the meantime, creating a demand on efficient and low profile antennas which can be integrated on a printed circuit board. The main objective of this thesis is to study, design, analyze and implement UWB low profile microstrip patch antenna that satisfy UWB technology requirements. Some methods to extend the bandwidth and other antenna parameters associated with wideband usages are studied. Several techniques are used for optimal UWB bandwidth performance of the UWB microstrip patch antenna. The performance parameters such as VSWR, Gain and radiation pattern of the UWB microstrip patch antenna is extensively investigated with simulations using FEKO. A set of simple design guidelines is proposed to provide approximate rules that result in optimum "first-pass" designs of probe-fed, miniaturized, low profile, microstrip UWB antennas using different bandwidth-enhancement techniques to satisfy UWB bandwidth that require minimal tuning.

Dandu, Varun Kumar

111

A compact ultra wideband antenna with WiMax band rejection for energy scavenging  

NASA Astrophysics Data System (ADS)

Radio Frequency (RF) energy harvesting has been rapidly advancing as a promising alternative to existing energy scavenging system. A well designed broadband antenna such as ultra-wideband (UWB) antenna can be used as one of the major components in an RF energy scavenging system. This paper presents a compact UWB antenna showing good impedance matching over a bandwidth of 2.8 to 11 GHz, suiTable for broadband RF energy scavenging. Nevertheless, the antenna usage in wireless communication has a limitation due to the problem of interference between UWB system and other narrowband systems. Thus, the proposed antenna is successfully designed with a single band-notched at the targeted WiMAX operating band of 3.3 to 3.6 GHz.

Jalil, Y. E.; Kasi, B.; Chakrabarty, C. K.

2013-06-01

112

Tightly-coupled GPS\\/UWB Integration  

Microsoft Academic Search

Ultra-wideband (UWB) ranging radios, an emerging technology that offers precise, short distance range measurements are investigated as a method to augment carrier-phase GPS positioning. A commercially available UWB ranging system is used in a tightly-coupled GPS and UWB real-time kinematic (RTK) system. The performance of the tightly-coupled system is evaluated in static and kinematic testing. This work demonstrates that UWB

Glenn Macgougan; Kyle O'Keefe; Richard Klukas

2010-01-01

113

Non-line of Sight Error Mitigation in Ultra-wideband Ranging Systems Using Biased Kalman Filtering  

Microsoft Academic Search

In this paper, a non-line of sight (NLOS) error mitigation method based on biased Kalman filtering for ultra-wideband (UWB)\\u000a ranging is proposed. The NLOS effect on the measures of signal arrival time is considered one of the major error sources in\\u000a range estimation and time-based wireless location systems. An improved biased Kalman filtering system, incorporated with sliding-window\\u000a data smoothing and

Chin-Der Wann; Chih-Sheng Hsueh

114

UWB delay and multiply receiver  

DOEpatents

An ultra-wideband (UWB) delay and multiply receiver is formed of a receive antenna; a variable gain attenuator connected to the receive antenna; a signal splitter connected to the variable gain attenuator; a multiplier having one input connected to an undelayed signal from the signal splitter and another input connected to a delayed signal from the signal splitter, the delay between the splitter signals being equal to the spacing between pulses from a transmitter whose pulses are being received by the receive antenna; a peak detection circuit connected to the output of the multiplier and connected to the variable gain attenuator to control the variable gain attenuator to maintain a constant amplitude output from the multiplier; and a digital output circuit connected to the output of the multiplier.

Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

2013-09-10

115

Channel estimation for ultra-wideband communications  

Microsoft Academic Search

This paper deals with channel estimation in ultra-wideband communications operating in a multipath environment and in the presence of multiaccess interference. The channel parameters are the attenuations and delays incurred by the signal echoes along the propagation paths. Time-hopping modulation with binary symbols is assumed. The estimation method is based on the maximum-likelihood criterion and is applied to two different

Vincenzo Lottici; A. D'Andrea; U. Mengali

2002-01-01

116

Pulse generator and BPSK modulator design for CMOS UWB transmitters  

Microsoft Academic Search

This paper presents a tunable Gaussian Pulse Generator and a BPSK modulator topology for use in CMOS UWB transmitters. The Pulse Generator exploits the Voltage Transfer Characteristic of a modified CMOS inverter, while the BPSK modulator guarantees superior matching between positive and negative pulses and supports high data rates at low power consumption, since its functional operation is in the

Michail Papamichail; Dimitrios Mavridis; George Papadopoulos

2009-01-01

117

Fiber-distributed Ultra-wideband noise radar with steerable power spectrum and colorless base station.  

PubMed

A fiber-distributed Ultra-wideband (UWB) noise radar was achieved, which consists of a chaotic UWB noise source based on optoelectronic oscillator (OEO), a fiber-distributed transmission link, a colorless base station (BS), and a cross-correlation processing module. Due to a polarization modulation based microwave photonic filter and an electrical UWB pass-band filter embedded in the feedback loop of the OEO, the power spectrum of chaotic UWB signal could be shaped and notch-filtered to avoid the spectrum-overlay-induced interference to the narrow band signals. Meanwhile, the wavelength-reusing could be implemented in the BS by means of the distributed polarization modulation-to-intensity modulation conversion. The experimental comparison for range finding was carried out as the chaotic UWB signal was notch-filtered at 5.2 GHz and 7.8 GHz or not. Measured results indicate that space resolution with cm-level could be realized after 3-km fiber transmission thanks to the excellent self-correlation property of the UWB noise signal provided by the OEO. The performance deterioration of the radar raised by the energy loss of the notch-filtered noise signal was negligible. PMID:24663829

Zheng, Jianyu; Wang, Hui; Fu, Jianbin; Wei, Li; Pan, Shilong; Wang, Lixian; Liu, Jianguo; Zhu, Ninghua

2014-03-10

118

SEMICONDUCTOR INTEGRATED CIRCUITS: A 6-9 GHz ultra-wideband CMOS PA for China's ultra-wideband standard  

NASA Astrophysics Data System (ADS)

A 6-9 GHz ultra-wideband CMOS power amplifier (PA) for the high frequency band of China's UWB standard is proposed. Compared with the conventional band-pass filter wideband input matching methodology, the number of inductors is saved by the resistive feedback complementary amplifying topology presented. The output impendence matching network utilized is very simple but efficient at the cost of only one inductor. The measured S22 far exceeds that of similar work. The PA is designed and fabricated with TSMC 0.18 ?m 1P6M RF CMOS technology. The implemented PA achieves a power gain of 10 dB with a ripple of 0.6 dB, and S11 < -10 dB over 6-9 GHz, S22 < -35 dB over 4-10 GHz. The measured output power at the 1 dB compression point is over 3.5 dBm from 6 to 9 GHz. The PA dissipates a total power of 21 mW from a 1.8 V power supply. The chip size is 1.1 × 0.8 mm2.

Zhendong, Gao; Zhiqiang, Li; Haiying, Zhang

2010-09-01

119

Ultra-wideband horn antenna with abrupt radiator  

DOEpatents

An ultra-wideband horn antenna transmits and receives impulse waveforms for short-range radars and impulse time-of flight systems. The antenna reduces or eliminates various sources of close-in radar clutter, including pulse dispersion and ringing, sidelobe clutter, and feedline coupling into the antenna. Dispersion is minimized with an abrupt launch point radiator element; sidelobe and feedline coupling are minimized by recessing the radiator into a metallic horn. Low frequency cut-off associated with a horn is extended by configuring the radiator drive impedance to approach a short circuit at low frequencies. A tapered feed plate connects at one end to a feedline, and at the other end to a launcher plate which is mounted to an inside wall of the horn. The launcher plate and feed plate join at an abrupt edge which forms the single launch point of the antenna.

McEwan, Thomas E. (Livermore, CA)

1998-01-01

120

Ultra-wideband horn antenna with abrupt radiator  

DOEpatents

An ultra-wideband horn antenna transmits and receives impulse waveforms for short-range radars and impulse time-of flight systems. The antenna reduces or eliminates various sources of close-in radar clutter, including pulse dispersion and ringing, sidelobe clutter, and feedline coupling into the antenna. Dispersion is minimized with an abrupt launch point radiator element; sidelobe and feedline coupling are minimized by recessing the radiator into a metallic horn. Low frequency cut-off associated with a horn is extended by configuring the radiator drive impedance to approach a short circuit at low frequencies. A tapered feed plate connects at one end to a feedline, and at the other end to a launcher plate which is mounted to an inside wall of the horn. The launcher plate and feed plate join at an abrupt edge which forms the single launch point of the antenna. 8 figs.

McEwan, T.E.

1998-05-19

121

Analysis of Ultra-wideband Impulse Radio Over Multimode Fiber Ranging System  

NASA Astrophysics Data System (ADS)

Ultra-wideband impulse radio (UWB-IR)-based systems are well known for their inherent capability to provide accurate ranging [1-3]. Remote positioning of such systems using Radio over MultiMode Fiber (RoMMF) technology is advantageous, for it provides a cost-effective way of system deployment by the consolidation of head-end equipment. In this chapter, we describe the details of a system model for evaluating the performance of a ranging system employing UWB-IR over multimode fiber. As the system uses low data rate digital communication to obtain range information, its quality can be studied using Bit Error Ratio (BER). This model combines wireless and radio over fiber sections of the system to predict system performance in terms of BER.

George, J.; Thelen, D.; Chamarti, A.; Ng'oma, A.; Sauer, M.

122

Ultra-Wideband Time-Difference-of-Arrival High Resolution 3D Proximity Tracking System  

NASA Technical Reports Server (NTRS)

This paper describes a research and development effort for a prototype ultra-wideband (UWB) tracking system that is currently under development at NASA Johnson Space Center (JSC). The system is being studied for use in tracking of lunar./Mars rovers and astronauts during early exploration missions when satellite navigation systems are not available. U IATB impulse radio (UWB-IR) technology is exploited in the design and implementation of the prototype location and tracking system. A three-dimensional (3D) proximity tracking prototype design using commercially available UWB products is proposed to implement the Time-Difference- Of-Arrival (TDOA) tracking methodology in this research effort. The TDOA tracking algorithm is utilized for location estimation in the prototype system, not only to exploit the precise time resolution possible with UWB signals, but also to eliminate the need for synchronization between the transmitter and the receiver. Simulations show that the TDOA algorithm can achieve the fine tracking resolution with low noise TDOA estimates for close-in tracking. Field tests demonstrated that this prototype UWB TDOA High Resolution 3D Proximity Tracking System is feasible for providing positioning-awareness information in a 3D space to a robotic control system. This 3D tracking system is developed for a robotic control system in a facility called "Moonyard" at Honeywell Defense & System in Arizona under a Space Act Agreement.

Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Phan, Chau; Dekome, Kent; Dusl, John

2010-01-01

123

Equalization for DS-UWB Systems—Part I: BPSK Modulation  

Microsoft Academic Search

Ultra-wideband wireless transmission has attracted considerable attention both in academia and industry. For high-rate and short-range transmission, direct sequence based ultra-wideband (DS-UWB) systems are a strong contender for consumer market applications. Due to the large transmission bandwidth, the UWB channel is characterized by a long root-mean-square delay spread and the RAKE receiver cannot always overcome the resulting intersymbol interference. We

Ambuj Parihar; Lutz Lampe; Robert Schober; Cyril Leung

2007-01-01

124

Time of arrival estimation for range-based localization in UWB sensor networks  

Microsoft Academic Search

Accurate Localization has gained significant interest within sensor networks recently and positioning systems based on Ultra-Wideband (UWB) technology have been considered, because the UWB signals have a very good accuracy due to the high time resolution (large bandwidth). Time of Arrival (TOA) estimation of the first path is usually used for range-based localization in realistic environments within UWB sensor networks,

Guowei Shen; Rudolf Zetik; Honghui Yan; Ole Hirsch; Reiner S. Thomä

2010-01-01

125

Waveform Analysis of UWB GPR Antennas.  

PubMed

Ground Penetrating Radar (GPR) systems fall into the category of ultra-wideband (UWB) devices. Most GPR equipment covers a frequency range between an octave and a decade by using short-time pulses. Each signal recorded by a GPR gathers a temporal log of attenuated and distorted versions of these pulses (due to the effect of the propagation medium) plus possible electromagnetic interferences and noise. In order to make a good interpretation of this data and extract the most possible information during processing, a deep knowledge of the wavelet emitted by the antennas is essential. Moreover, some advanced processing techniques require specific knowledge of this signal to obtain satisfactory results. In this work, we carried out a series of tests in order to determine the source wavelet emitted by a ground-coupled antenna with a 500 MHz central frequency. PMID:22573965

Rial, Fernando I; Lorenzo, Henrique; Pereira, Manuel; Armesto, Julia

2009-01-01

126

Ultra-wideband CMOS-MEMS radio  

Microsoft Academic Search

Current ultrawideband (UWB) radios have several unsolved issues in front-end performance including difficult and expensive clock synthesizer designs, and power hungry baseband functions. In fact, the expected breakthrough of the very useful UWB technology has stalled since realized high bitrate integrated radios are much too expensive in the sense that they dissipate a lot of DC power and that their

Esa Tiiliharju; Tero Koivisto; Janne Maunu; N. Chekurovy; I. Tittoneny

2009-01-01

127

Small and Broadband Planar Antennas for UWB Wireless Communication Applications  

NASA Astrophysics Data System (ADS)

Due to the unique features of ultra-wideband (UWB) wireless communication systems, the antenna design with small size and broad band-widths for transfer response and systems gain are required. A novel rolled planar antenna is proposed to meet the requirements for omni-directional UWB wireless communication applications.

Chen, Z. N.

128

UWB Microwave Monopulse Radar System for breast cancer detection  

Microsoft Academic Search

The concept of an Ultra Wideband (UWB) Monopulse Microwave Radar System for detection and location of breast cancer is described. The system uses a two-element Tapered Slot Antenna (TSA) array accompanied by a UWB 180° hybrid which scans the breast. When the breast tissue features symmetry with respect to the array axis and the hybrid enables the 180° out phase

Marek E. Bialkowski; Yifan Wang; Amin Abbosh

2010-01-01

129

Generalized equivalent circuit model for ultra wideband antenna structure with double steps for energy scavenging  

NASA Astrophysics Data System (ADS)

There are various types of UWB antennas can be used to scavenge energy from the air and one of them is the printed disc monopole antenna. One of the new challenges imposed on ultra wideband is the design of a generalized antenna circuit model. It is developed in order to extract the inductance and capacitance values of the UWB antennas. In this research work, the developed circuit model can be used to represent the rectangular printed disc monopole antenna with double steps. The antenna structure is simulated with CST Microwave Studio, while the circuit model is simulated with AWR Microwave Office. In order to ensure the simulation result from the circuit model is accurate, the circuit model is also simulated using Mathlab program. The developed circuit model is found to be able to depict the actual UWB antenna. Energy harvesting from environmental wirelessly is an emerging method, which forms a promising alternative to existing energy scavenging system. The developed UWB can be used to scavenge wideband energy from electromagnetic wave present in the environment.

>Oon Kheng Heong, Goh Chin; Chakrabarty, Chandan Kumar; >Goh Tian Hock,

2013-06-01

130

A CMOS Ultra-Wideband Impulse Radio Transceiver for 1Mb\\/s Data Communications and $pm$ 2.5-cm Range Finding  

Microsoft Academic Search

A CMOS ultra-wideband impulse radio (UWB-IR) transceiver was developed in 0.18- m CMOS technology. It can be used for 1-Mb\\/s data communications as well as for precise range finding within an error of 2.5 cm. The power consumptions of the transmitter and receiver for data communication are 0.7 and 4.0 mW, respectively. When an LNA operates intermittently through bias switching,

Takahide Terada; Shingo Yoshizumi; Muhammad Muqsith; Yukitoshi Sanad; Tadahiro Kuroda

2006-01-01

131

Balanced pulse generator for UWB radar application  

Microsoft Academic Search

A balanced pulse generator delivering high repetitive pulses of high voltage amplitude and pulse widths in the picosecond region is described. The output pulses of a npn silicon power transistor operating in an avalanche mode, drive a step recovery diode (SRD) waveform edge sharpener. As commercially available ultra-fast SRDs have commonly low breakdown voltage, the powerful avalanche pulses with a

Ahmed Abbas H. Ameri; Gunter Kompa; Axel Bangert

2011-01-01

132

3D positioning scheme exploiting nano-scale IR-UWB orthogonal pulses  

PubMed Central

In these days, the development of positioning technology for realizing ubiquitous environments has become one of the most important issues. The Global Positioning System (GPS) is a well-known positioning scheme, but it is not suitable for positioning in in-door/building environments because it is difficult to maintain line-of-sight condition between satellites and a GPS receiver. To such problem, various positioning methods such as RFID, WLAN, ZigBee, and Bluetooth have been developed for indoor positioning scheme. However, the majority of positioning schemes are focused on the two-dimension positioning even though three-dimension (3D) positioning information is more useful especially in indoor applications, such as smart space, U-health service, context aware service, etc. In this paper, a 3D positioning system based on mutually orthogonal nano-scale impulse radio ultra-wideband (IR-UWB) signals and cross array antenna is proposed. The proposed scheme uses nano-scale IR-UWB signals providing fine time resolution and high-resolution multiple signal specification algorithm for the time-of-arrival and the angle-of-arrival estimation. The performance is evaluated over various IEEE 802.15.4a channel models, and simulation results show the effectiveness of proposed scheme.

2011-01-01

133

3D positioning scheme exploiting nano-scale IR-UWB orthogonal pulses  

NASA Astrophysics Data System (ADS)

In these days, the development of positioning technology for realizing ubiquitous environments has become one of the most important issues. The Global Positioning System (GPS) is a well-known positioning scheme, but it is not suitable for positioning in in-door/building environments because it is difficult to maintain line-of-sight condition between satellites and a GPS receiver. To such problem, various positioning methods such as RFID, WLAN, ZigBee, and Bluetooth have been developed for indoor positioning scheme. However, the majority of positioning schemes are focused on the two-dimension positioning even though three-dimension (3D) positioning information is more useful especially in indoor applications, such as smart space, U-health service, context aware service, etc. In this paper, a 3D positioning system based on mutually orthogonal nano-scale impulse radio ultra-wideband (IR-UWB) signals and cross array antenna is proposed. The proposed scheme uses nano-scale IR-UWB signals providing fine time resolution and high-resolution multiple signal specification algorithm for the time-of-arrival and the angle-of-arrival estimation. The performance is evaluated over various IEEE 802.15.4a channel models, and simulation results show the effectiveness of proposed scheme.

Kim, Nammoon; Kim, Youngok

2011-10-01

134

Ultra-wideband electronics, design methods, algorithms, and systems for dielectric spectroscopy of isolated B16 tumor cells in liquid medium  

NASA Astrophysics Data System (ADS)

Quantifying and characterizing isolated tumor cells (ITCs) is of interest in surgical pathology and cytology for its potential to provide data for cancer staging, classification, and treatment. Although the independent prognostic significance of circulating ITCs has not been proven, their presence is gaining clinical relevance as an indicator. However, researchers have not established an optimal method for detecting ITCs. Consequently, this Ph.D. dissertation is concerned with the development and evaluation of dielectric spectroscopy as a low-cost method for cell characterization and quantification. In support of this goal, ultra-wideband (UWB), microwave pulse generator circuits, coaxial transmission line fixtures, permittivity extraction algorithms, and dielectric spectroscopy measurement systems were developed for evaluating the capacity to quantify B16-F10 tumor cells in suspension. First, this research addressed challenges in developing tunable UWB circuits for pulse generation. In time-domain dielectric spectroscopy, a tunable UWB pulse generator facilitates exploration of microscopic dielectric mechanisms, which contribute to dispersion characteristics. Conventional approaches to tunable pulse generator design have resulted in complex circuit topologies and unsymmetrical waveform morphologies. In this research, a new design approach for low-complexity, tunable, sub-nanosecond and UWB pulse generator was developed. This approach was applied to the development of a novel generator that produces symmetrical waveforms (patent pending 60/597,746). Next, this research addressed problems with transmission-reflection (T/R) measurement of cell suspensions. In T/R measurement, coaxial transmission line fixtures have historically required an elaborate sample holder for containing liquids, resulting in high cost and complexity. Furthermore, the algorithms used to extract T/R dielectric properties have suffered from myriad problems including local minima and halfwavelength resonance. In this dissertation, a simple coaxial transmission line fixture for holding liquids by dispensing with the air-core assumption inherent in previous designs was developed (patent pending 60/916,042). In addition, a genetic algorithm was applied towards extracting dielectric properties from measurement data to circumvent problems of local minima and half wavelength resonance. Finally, in this research the capacity for using dielectric properties to quantify isolated B16-F10 tumor cells in McCoy's liquid medium was investigated. In so doing, the utility of the Maxwell-Wagner mixture formula for cell quantification was demonstrated by measuring distinct dielectric properties for differing volumes of cell suspensions using frequency- and time-domain dielectric spectroscopy.

Maxwell, Erick N.

135

Ultra wideband ground penetrating radar imaging of heterogeneous solids  

DOEpatents

A non-invasive imaging system for analyzing engineered structures comprises pairs of ultra wideband radar transmitters and receivers in a linear array that are connected to a timing mechanism that allows a radar echo sample to be taken at a variety of delay times for each radar pulse transmission. The radar transmitters and receivers are coupled to a position determining system that provides the x,y position on a surface for each group of samples measured for a volume from the surface. The radar transmitter and receivers are moved about the surface, e.g., attached to the bumper of a truck, to collect such groups of measurements from a variety of x,y positions. Return signal amplitudes represent the relative reflectivity of objects within the volume and the delay in receiving each signal echo represents the depth at which the object lays in the volume and the propagation speeds of the intervening material layers. Successively deeper z-planes are backward propagated from one layer to the next with an adjustment for variations in the expected propagation velocities of the material layers that lie between adjacent z-planes.

Warhus, John P. (Brentwood, CA); Mast, Jeffrey E. (Livermore, CA)

1998-01-01

136

Ultra wideband ground penetrating radar imaging of heterogeneous solids  

DOEpatents

A non-invasive imaging system for analyzing engineered structures comprises pairs of ultra wideband radar transmitters and receivers in a linear array that are connected to a timing mechanism that allows a radar echo sample to be taken at a variety of delay times for each radar pulse transmission. The radar transmitters and receivers are coupled to a position determining system that provides the x,y position on a surface for each group of samples measured for a volume from the surface. The radar transmitter and receivers are moved about the surface, e.g., attached to the bumper of a truck, to collect such groups of measurements from a variety of x,y positions. Return signal amplitudes represent the relative reflectivity of objects within the volume and the delay in receiving each signal echo represents the depth at which the object lays in the volume and the propagation speeds of the intervening material layers. Successively deeper z-planes are backward propagated from one layer to the next with an adjustment for variations in the expected propagation velocities of the material layers that lie between adjacent z-planes. 11 figs.

Warhus, J.P.; Mast, J.E.

1998-11-10

137

UWB Spatial-Frequency Channel Characterization  

Microsoft Academic Search

This paper investigates the spatial-frequency chan- nel characterization of Ultra-wideband (UWB) wireless commu- nication systems. Firstly, a novel frequency dependent UWB channel model is constructed based on the theory of electro- magnetic diffraction mechanism, which causes the field strength to vary with the frequency in each multipath. Secondly, we build a space-frequency model, which includes spatial characteristics such as angular

Wen Zhang; Thushara D. Abhayapala; Jian Zhang

138

Generation of Arbitrary UWB Waveforms by Spectral Pulse Shaping and Thermally-Controlled Apodized FBGs  

Microsoft Academic Search

We propose and experimentally demonstrate an arbitrary UWB pulse generator. The proposed technique is based on spectral pulse shaping and frequency-to-time conversion. The reconfigurability of this technique comes from changing the apodizaton of a chirped fiber Bragg grating (FBG) using a series of heating elements (HE). By setting the appropriate temperature set to the HEs, any predesigned UWB waveforms can

Mohammad Abtahi; Mansour Dastmalchi; Sophie Larochelle; Leslie A. Rusch

2009-01-01

139

Accurate UWB indoor localization system utilizing time difference of arrival approach  

Microsoft Academic Search

An accurate ultra wideband (UWB) localization approach has been developed based on time difference of arrival (TDOA). This method provides sub-cm accuracy, which is excellent for indoor utilization when compared with frequency modulated continuous wave (FMCW) systems. The system is also in compliance with FCC UWB regulations and achieves accurate ranging measurements. The utilized time domain measurements suppress multipath signals

C. Zhang; M. Kuhn; B. Merkl; A. E. Fathy; M. Mahfouz

2006-01-01

140

Study on multiband UWB system via WPMCM in the context of cognitive radio  

Microsoft Academic Search

Cognitive radio (CR) introduces the opportunistic usage of frequency bands and Orthogonal frequency division multiplexing (OFDM) is a strong candidate for CR design. Ultra wideband (UWB) radio fulfills some of the key cognitive radio requirements. Regarding the power limitations for UWB systems the main challenging issue is the impact of narrowband interference (NBI). Wavelet packet transform (WPT) is a possible

Haleh Hosseini; Norsheila Fisal; Sharifah K. Syed-Yusof

2009-01-01

141

Evaluation of the interference of pulsed UWB signals over current services in CATV installations  

Microsoft Academic Search

This paper presents an application of ultra- wide band (UWB) technology, consisting on the injection of pulsed UWB signals on community antenna television (CATV) installations. This approach offers the cable installers the possibility for a wide range of new data and multimedia channels on existing CATV installations, with a minimum cost and without altering the transmission of the traditional radio

Julen Ugalde; Inaki Val; Pedro Crespo

2008-01-01

142

Ultra-Wideband Sensors for Improved Magnetic Resonance Imaging, Cardiovascular Monitoring and Tumour Diagnostics  

PubMed Central

The specific advantages of ultra-wideband electromagnetic remote sensing (UWB radar) make it a particularly attractive technique for biomedical applications. We partially review our activities in utilizing this novel approach for the benefit of high and ultra-high field magnetic resonance imaging (MRI) and other applications, e.g., for intensive care medicine and biomedical research. We could show that our approach is beneficial for applications like motion tracking for high resolution brain imaging due to the non-contact acquisition of involuntary head motions with high spatial resolution, navigation for cardiac MRI due to our interpretation of the detected physiological mechanical contraction of the heart muscle and for MR safety, since we have investigated the influence of high static magnetic fields on myocardial mechanics. From our findings we could conclude, that UWB radar can serve as a navigator technique for high and ultra-high field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it can potentially be used to support standard ECG analysis by complementary information where sole ECG analysis fails. Further analytical investigations have proven the feasibility of this method for intracranial displacements detection and the rendition of a tumour’s contrast agent based perfusion dynamic. Beside these analytical approaches we have carried out FDTD simulations of a complex arrangement mimicking the illumination of a human torso model incorporating the geometry of the antennas applied.

Thiel, Florian; Kosch, Olaf; Seifert, Frank

2010-01-01

143

Performance Evaluation of a UWB-RFID System for Potential Space Applications  

NASA Technical Reports Server (NTRS)

This talk presents a brief overview of the ultra-wideband (UWB) RFID system with emphasis on the performance evaluation of a commercially available UWB-RFID system. There are many RFID systems available today, but many provide just basic identification for auditing and inventory tracking. For applications that require high precision real time tracking, UWB technology has been shown to be a viable solution. The use of extremely short bursts of RF pulses offers high immunity to interference from other RF systems, precise tracking due to sub-nanosecond time resolution, and robust performance in multipath environments. The UWB-RFID system Sapphire DART (Digital Active RFID & Tracking) will be introduced in this talk. Laboratory testing using Sapphire DART is performed to evaluate its capability such as coverage area, accuracy, ease of operation, and robustness. Performance evaluation of this system in an operational environment (a receiving warehouse) for inventory tracking is also conducted. Concepts of using the UWB-RFID technology to track astronauts and assets are being proposed for space exploration.

Phan, Chan T.; Arndt, D.; Ngo, P.; Gross, J.; Ni, Jianjun; Rafford, Melinda

2006-01-01

144

System development and performance evaluation on detection schemes for UWB-IR implant communications.  

PubMed

Ultra wideband-impulse radio (UWB-IR) transmission is one of promising transmission technologies in implant body area networks (BANs). Although some studies have investigated the channel model and communication architecture in implant BANs, no study quantitatively shows the feasibility of UWB-IR communication in the human body with actual developed transceivers at a high data rate. In this paper, we focus on experimental evaluation of the correlation detection (coherent detection) and the energy detection (non-coherent detection) for UWB-IR transmission with multi-pulse position modulation (MPPM). For this purpose, we develop a UWB-IR communication system with MPPM scheme, and experimentally evaluate the transmission performance of the developed systems with the two different detection schemes. In addition to the experimental evaluation, we also theoretically analyze the bit error rate (BER) performance by using Gaussian approximation. From the experimental results, the developed system has achieved a BER of 10(-2) at the propagation loss of 75 dB with a data rate of 2Mbps in the correlation detection. This result shows the feasibility of reliable UWB-IR communication in actual implant BANs. PMID:24109917

Katsu, Kenta; Anzai, Daisuke; Wang, Jianqing

2013-01-01

145

Effects of a Radome on a UWB Detection System.  

National Technical Information Service (NTIS)

We evaluated a radome housing an ultra-wideband (UWB) signal collection system, measuring the transmission loss and phase delay through the radome. The radome introduced losses of up to 3 dB within the normal operating range of the antennas. Phase differe...

M. Litz R. D. del Rosario K. Leshick

1998-01-01

146

THE DESIGN OF UWB ANTENNA USING LOG-PERIODIC TECHNIQUE  

Microsoft Academic Search

This paper described the design, simulation and fabrication of the Ultra Wideband (UWB) antennas using seventeen elements log-periodic (LP) technique. The antennas have been modeled using microstrip lines and S parameter data from individual single element. The data is extracted from the momentum simulation and combined with the microstrip transmission line. The properties of antennas such as bandwidth return loss

M. K. A. Rahim; M. R. Ahmad; A. Asrokin; M. Z. A. A. Aziz

147

A low cost UWB printed dipole antenna with high performance  

Microsoft Academic Search

This paper introduces a new ultra-wideband (UWB) printed circular dipole antenna with a hidden feed line. The specific feeding removes any radiation pattern disturbance generally met with this kind of antenna when fed with a coaxial or a microstrip line. The dipole is smaller than a quarter-wavelength unlike more traditional dipole. For a low cost realization, the antenna has been

E. Gueguen; F. Thudor; P. Chambelin

2005-01-01

148

Focus of attention for millimeter and ultra wideband synthetic aperture radar imagery  

NASA Astrophysics Data System (ADS)

The major goal of this research is to develop efficient detectors for Synthetic Aperture Radar (SAR) images, exploiting the reflectivity characteristics of targets in different radar types. Target detection is a signal processing problem whereby one attempts to detect a stationary target embedded in background clutter while minimizing the false alarm probability. In radar signal processing, the better resolution provided by the Millimeter Wave (MMW) SAR enhances the detectability of small targets. As radar technology evolves, the newly developed Ultra Wideband (UWB) SAR provides better penetration capabilities to locate concealed targets in foliage. In this thesis we demonstrate that local intensity kernel tests can be formulated based on the generalized likelihood ratio test (GLRT), while preserving constant false alarm rate (CFAR) characteristics. Both the widely used two-parameter CFAR and the g -CFAR can be viewed as special cases of the local intensity tests with different intensity kernels. It is demonstrated that the first-order Gamma kernel is a good approximation for the principal eigenvector of the projected radial intensity of targets, which provides the optimal matching intensity kernel. This also explains the better performance of the g -CFAR detector over the two parameter CFAR detector. We also developed different CFAR subspace detectors for UWB images, utilizing a Laguerre function subspace. The driven response produced by natural clutter degrades the performance of these subspace detectors. In addition to the driven response, the distinguishing feature of metallic targets in UWB is the resonance response. Therefore, we further propose a two-stage detection scheme: g -CFAR detector followed by the quadratic Laguerre discriminator (QLD). We evaluate every detector and discriminator using ROC curves in a large area (about 2 km2) of imagery. The combined g -CFAR and quadratic Laguerre discriminator improve the simple Laguerre subspace detector more than one hundred fold for a perfect detection rate (Pd = 1).

Yen, Li-Kang

149

A low complexity MMSE-RAKE receiver in a realistic UWB channel and in the presence of NBI  

Microsoft Academic Search

Ultra-wideband (UWB) radio systems have attracted a lot of attention during the last few years. These systems are very low transmission power and spread over a bandwidth of several gigahertz. The very low transmission power and the large bandwidth used, enable a UWB system to co-exist with other narrow band systems. Nevertheless, these narrow band systems may cause interference, which

N. Boubaker; K. B. Letaief

2003-01-01

150

Liquid and moisture sensing by ultra-wideband pseudo-noise sequence signals  

NASA Astrophysics Data System (ADS)

The use of ultra-wideband signals for moisture sensing by electromagnetic wave interaction provides more information on the material under test compared to single tone or narrowband approaches, regarding spatial and frequency dependent phenomena. Current activities to regulate the emission of electromagnetic waves in the spectral band up to 10 GHz for sensor applications open new perspectives for microwave moisture sensing. Therefore, improved and cost effective ultra-wideband measurement principles will become more and more interesting. The use of short pulses or swept sine waves are classic approaches to cover a large spectral band. However, this paper deals with some variants of an alternative method, which applies pseudo-random codes, namely M-sequences, to stimulate the test objects. The method permits monolithic integration of the RF-electronics in SiGe technology. The signal generation and data capturing are referred to a common stable single tone clock and they are controlled by steep trigger signals. This provides for very stable operation, which allows for measurements in both time and frequency domain. Two versions of an M-sequence approach will be considered and their functioning will be demonstrated by means of simple measurement examples.

Sachs, J.; Peyerl, P.; Wöckel, S.; Kmec, M.; Herrmann, R.; Zetik, R.

2007-04-01

151

Ultra-wideband low-cost phased-array radars  

Microsoft Academic Search

Emerging radar applications require phased arrays that can operate over wide bandwidths to support multiband\\/multifunction operation. In response to that need, this paper presents a cost-effective implementation for extremely wide-band phased-array radars. Two designs are demonstrated, one operating from 3 to 12 GHz and the other operating from 8 to 20 GHz. These designs incorporate ultra-wideband antipodal tapered slot antennas,

Christopher T. Rodenbeck; Sang-Gyu Kim; Wen-Hua Tu; Matthew R. Coutant; Seungpyo Hong; Mingyi Li; Kai Chang

2005-01-01

152

Ultra-wideband spectral analysis using S2 technology  

Microsoft Academic Search

This paper outlines the efforts to develop an ultra-wideband spectrum analyzer that takes advantage of the broad spectral response and fine spectral resolution (?25kHz) of spatial-spectral (S2) materials. The S2 material can process the full spectrum of broadband microwave transmissions, with adjustable time apertures (down to 100?s) and fast update rates (up to 1kHz). A cryogenically cooled Tm:YAG crystal that

R. Krishna Mohan; T. Chang; M. Tian; S. Bekker; A. Olson; C. Ostrander; A. Khallaayoun; C. Dollinger; W. R. Babbitt; Z. Cole; R. R. Reibel; K. D. Merkel; Y. Sun; R. Cone; F. Schlottau; K. H. Wagner

2007-01-01

153

Ultra-wideband Active Receiving Array Antenna with Dual Polarization  

NASA Astrophysics Data System (ADS)

This chapter presents results of the investigations directed to creation of large ultra-wideband active receiving array antennas with dual polarization. The array element is made on the basis of two crossed electric dipoles. Each arm of the dipoles is loaded to the single-stage FET amplifier. Four such elements form a 2 × 2 module being a component of a multielement array antenna.

Koshelev, V. I.; Balzovsky, E. V.; Buyanov, Yu. I.

154

LTCC-based ultra-wideband Linearly Tapered Slot Antenna design guidelines  

Microsoft Academic Search

In this paper, the design of antipodal non-planar linearly tapered slot antenna (LTSA) designed in LTCC technology with wide bandwidth operation for ultra-wideband applications and a practical design guideline of LTCC-based ultra wideband LTSA is presented. The LTCC-based ultra wideband LTSA characteristics are investigated and then compared to a compact antipodal LTCC-based Vivaldi design. Using microstrip feeding technique, the antenna

Ziad El-Khatib; Leonard MacEachern; Samy A. Mahmoud

2009-01-01

155

A Decorrelating Multiuser Receiver for Transmit-Reference UWB Systems  

Microsoft Academic Search

Transmit-reference (TR) is known as a realistic but low data rate candidate for ultra-wideband (UWB) communication systems. This paper proposes a new TR-UWB scheme that uses a decorrelating receiver to enable higher data rates with only a reasonably small increase in complexity while still maintaining the ease of synchronization of the original. Integrate and dump with oversampling is used to

Quang Hieu Dang; Alle-Jan van der Veen

2007-01-01

156

The effect of NBI on UWB time-hopping systems  

Microsoft Academic Search

This letter presents an analysis of the effect of narrowband interference (NBI) on ultra-wideband (UWB) time-hopping (TH) systems in the presence of multipath fading using both analytical derivations and simulations. Our analysis demonstrates that NBI may be an issue in some instances. In addition we suggest three NBI suppression schemes for combating NBI in UWB TH systems. Single-link performance of

Xiaoli Chu; Ross D. Murch

2004-01-01

157

Integration of UWB and Wireless Pressure Mapping in Surgical Navigation  

Microsoft Academic Search

Wireless technologies are becoming more prevalent in hospital environments. An ultra-wideband (UWB) indoor tracking system is outlined, which has dynamic 3-D real-time root-mean-square error in the range of 5.24-6.37 mm using line-of-sight signals in different experiments. This high 3-D accuracy opens up many new applications to UWB indoor wireless positioning, which includes its use for tracking smart surgical tools and

Mohamed R. Mahfouz; Michael J. Kuhn; Gary To; Aly E. Fathy

2009-01-01

158

UWB ranging with antenna proximity to the human head  

Microsoft Academic Search

Time-of-arrival (ToA) estimation used with ultra-wideband (UWB) technology has become the most popular technique for accurate indoor localization. Much work has been done on UWB ToA estimation in general. However, the effect of the radiation patterns of antennas used in localization applications have not been considered. This paper investigates the effect of user terminal (UT) antenna pattern on the detection

Marzieh Dashti; Afroza Khatun; Tommi Laitinen; A. A. H. Azremi; K. Haneda; M. Ghoraishi; J.-i. Takada

2010-01-01

159

Development of an UWB Indoor 3D Positioning Radar with Millimeter Accuracy  

Microsoft Academic Search

A high resolution ultra wideband (UWB) positioning radar system based on time difference of arrival (TDOA) has been developed. The UWB radar system provides millimeter accuracy in dense multipath indoor environments for 1D, 2D, and 3D localization. The system is fully compliant with the FCC UWB regulations and utilizes time domain measurements to suppress both multipath signals and non-line of

Cemin Zhang; M. Kuhn; B. Merkl; M. Mahfouz; A. E. Fathy

2006-01-01

160

MMSE multipath diversity combining for multi-access TH-UWB in the presence of NBI  

Microsoft Academic Search

The performance of asynchronous time-hopping ultra-wideband (TH-UWB) multiple access spread spectrum is analytically investigated in a UWB realistic multipath channel and in the presence of narrowband interference (NBI). In particular, an interference suppression receiver for TH-UWB wireless systems is proposed. It consists of selecting the first strongest multipath components using an appropriate Rake receiver with the path diversity combining being

Nejib Boubaker; Khaled Ben Letaief

2006-01-01

161

Reduced complexity demodulation and equalization scheme for differential Impulse Radio UWB Systems with ISI  

Microsoft Academic Search

In this paper, we consider the demodulation and equalization problem of differential impulse radio (IR) ultra-wideband (UWB) Systems with inter-symbol-interference (ISI). The differential IR UWB systems have been extensively discussed recently. The advantage of differential IR UWB systems include simple receiver frontend structure. One challenge in the demodulation and equalization of such systems with ISI is that the systems have

Xudong Ma

2009-01-01

162

People Tracking with UWB Radar Using a Multiple-Hypothesis Tracking of Clusters (MHTC) Method  

Microsoft Academic Search

This paper presents a method to track multiple moving humans using Ultra-Wideband (UWB) radar. UWB radar can complement other\\u000a human tracking technologies, as it works well in poor visibility conditions. Our tracking approach is based on a point process\\u000a interpretation of the multi-path UWB radar scattering model for moving humans. Based on this model, we present a multiple\\u000a hypothesis tracking

SangHyun Chang; Rangoli Sharan; Michael T. Wolf; Naoki Mitsumoto; Joel W. Burdick

2010-01-01

163

New band-notched UWB antenna  

Microsoft Academic Search

A simple and compact ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed in this paper.\\u000a The antenna is partially grounded so that the Q value is depressed and the impedance bandwidth is broadened. A small strip bar is loaded on each arm of the similar U-shaped\\u000a radiator. The impedance bandwidth of the antenna overlap with IEEE 802.11a

Xiao-xiang He; Hong-wei Deng

2009-01-01

164

Blind UWB timing with a dirty template  

Microsoft Academic Search

Ultra-wideband (UWB) radio is gaining increasing attention thanks to its attractive features that include low-power low-complexity baseband operation and ample multipath diversity. Realization of its potential, however, faces the challenge of low-complexity high-performance timing acquisition. In this paper, we develop a blind timing acquisition algorithm for frame-level synchronization. Relying on simple integrate-and-dump operations over one symbol duration, our algorithm exploits

Liuqing Yang; Georgios B. Giannakis

2004-01-01

165

Amplify-and-Forward Cooperative Diversity for Green UWB-Based WBSNs  

PubMed Central

This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23?dB performance enhancement at 1e ? 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs.

2013-01-01

166

75 FR 62476 - Ultra-Wideband Transmission Systems  

Federal Register 2010, 2011, 2012, 2013

...employ frequency hopping or stepped frequency modulation techniques, or that...UWB or otherwise, employing stepped frequency, frequency hopping, or swept...that UWB transmitters employing stepped frequency, frequency hopping, or...

2010-10-12

167

Design and Performance Evaluation on Ultra-Wideband Time-Of-Arrival 3D Tracking System  

NASA Technical Reports Server (NTRS)

A three-dimensional (3D) Ultra-Wideband (UWB) Time--of-Arrival (TOA) tracking system has been studied at NASA Johnson Space Center (JSC) to provide the tracking capability inside the International Space Station (ISS) modules for various applications. One of applications is to locate and report the location where crew experienced possible high level of carbon-dioxide and felt upset. In order to accurately locate those places in a multipath intensive environment like ISS modules, it requires a robust real-time location system (RTLS) which can provide the required accuracy and update rate. A 3D UWB TOA tracking system with two-way ranging has been proposed and studied. The designed system will be tested in the Wireless Habitat Testbed which simulates the ISS module environment. In this presentation, we discuss the 3D TOA tracking algorithm and the performance evaluation based on different tracking baseline configurations. The simulation results show that two configurations of the tracking baseline are feasible. With 100 picoseconds standard deviation (STD) of TOA estimates, the average tracking error 0.2392 feet (about 7 centimeters) can be achieved for configuration Twisted Rectangle while the average tracking error 0.9183 feet (about 28 centimeters) can be achieved for configuration Slightly-Twisted Top Rectangle . The tracking accuracy can be further improved with the improvement of the STD of TOA estimates. With 10 picoseconds STD of TOA estimates, the average tracking error 0.0239 feet (less than 1 centimeter) can be achieved for configuration "Twisted Rectangle".

Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Dusl, John

2012-01-01

168

Ultra wideband direction finding using digital channelization receiver architecture  

Microsoft Academic Search

In this paper, UWB direction finding technique using digital channelization receiver architecture Is proposed. The basic idea of this technique is to split the UWB array output into multiple frequency channels and then down-convert each channel into much lower frequency, hence allowing the low sampling rate ADC to be used. Estimation of the DoA of UWB source is achieved by

Joni Polili Lie; Chong Meng See; Boon Poh Ng

2006-01-01

169

A dual slope based pulse position modulation circuit for sub-GHz IR-UWB systems  

Microsoft Academic Search

A pulse position modulation circuit for IR-UWB communication systems suitable for CMOS integration is proposed. The PN code representing the pulse position is converted into a corresponding analog voltage and compared with the outputs of two precision ramp generator circuits. The ramp generators employ a negative feedback principle making their output robust against environmental and process variations in order to

Varun Shenoy; Prasanna Kalkura; Sungyong Jung; Mingyu Lu; Jean Gao; Sung Chul Lee

2008-01-01

170

LowPower Sliding Correlation CMOS UWB Pulsed Radar Receiver for Motion Detection  

Microsoft Academic Search

This paper presents a lowpower coherent receiver for UWB pulsed Radar for motion detection. Due to accuracy of the radar motion detection, coherent detection scheme is adopted in the receiver. To relax the stringent requirement of timing synchronization, sliding correlation detection is proposed. The clocking step which determines detection resolution is determined by 2ns which is half of a pulse

Anh Tuan Phan; Ronan Farrell

171

A CPW-fed anti-interference UWB antenna using a stepped impedance stub loaded pentagon resonator  

Microsoft Academic Search

A coplanar waveguide (CPW) fed anti-interference ultra wideband (UWB) antenna is proposed numerically in this paper. The proposed UWB antenna has an anti-interference characteristic which is produced by using stepped impedance stub (SIS) loaded pentagon resonator (PR). The anti-interference function can reduce the potential interference between UWB systems and WLAN systems. The bandwidth of the proposed antenna was enhanced by

Yingsong Li; Wenxing Li; Si Li; Chengyuan Liu; Tao Jiang

2012-01-01

172

Performance evaluation for UWB signal transmission with different modulation schemes in multi-cell environment distributed using ROF technology  

Microsoft Academic Search

We describe a radio-over-fiber (ROF) based ultra-wideband (UWB) transmission system. In a multi-cell environment using ROF technology, the performance of UWB signal transmission with different modulation schemes is evaluated in a realistic channel model based on a modified ?-K model. Then, we investigate the effects of multipath interference and delay time at the overlapped area on the performance of UWB

Sangil Kim; Hodeok Jang; Seonghoon Choi; Yonghoon Kim; Jichai Jeong

2004-01-01

173

A NOVEL UNIPLANAR SUBHARMONIC MIXER FOR NEAR BASEBAND UWB APPLICATIONS  

Microsoft Academic Search

An ultra wideband uni-planar sub-harmonic mixer1 has been designed for ultra-wideband applications. This mixer is designed to operate at RF frequencies ranging from 8 to 12 GHz. The mixers IF frequency is nearly base-band as it covers an extremely wide range from 0.1GHz to 2GHz. Using short pulses as the IF signal would obtain some advantages over conventional narrow band

Song Lin; Yunqiang Yang; Aly E. Fathy

174

Three-Dimensional Planetary Surface Tracking Based on a Simple Ultra-Wideband Impulse-Radio Infrastructure  

NASA Technical Reports Server (NTRS)

Several prototype ultra-wideband (UWB) impulse-radio (IR) tracking systems are currently under development at NASA Johnson Space Center (JSC). These systems are being studied for use in tracking of Lunar/Mars rovers and astronauts during early exploration missions when satellite navigation systems (such as GPS) are not available. To date, the systems that have been designed and tested are intended only for two-dimensional location and tracking, but these designs can all be extended to three-dimensional tracking with only minor modifications and increases in complexity. In this presentation, we will briefly review the design and performance of two of the current 2-D systems: one designed specifically for short-range, extremely high-precision tracking (approximately 1-2 cm resolution) and the other designed specifically for much longer range tracking with less stringent precision requirements (1-2 m resolution). We will then discuss a new multi-purpose system design based on a simple UWB-IR architecture that can be deployed easily on a planetary surface to support arbitrary three-dimensional localization and tracking applications. We will discuss utilization of this system as an infrastructure to provide both short-range and long-range tracking and analyze the localization performance of the system in several different configurations. We will give theoretical performance bounds for some canonical system configurations and compare these performance bounds with both numerical simulations of the system as well as actual experimental system performance evaluations.

Barton, Richard J.; Ni, David; Ngo, Phong

2010-01-01

175

Ultra-Wideband Bandpass Filter with Sharp Attenuation Slope Using Inter-Digital Finger Resonator and Parallel-Coupled Lines  

NASA Astrophysics Data System (ADS)

This paper presents an ultra-wideband (UWB) bandpass filter (BPF) with sharp attenuation slope characteristics. The circuit structure consists of an inter-digital finger resonator, parallel-coupled lines and phase matching line. The design of the bandwidth was described by using the even and odd mode characteristic impedances in the resonator structure. The parallel-coupled lines were also designed in the same manner. The parameters of the resonator and two parallel-coupled lines in combination as the BPF were then optimized by the simulation with HFSS. The designed BPF was experimentally fabricated and its measured performances showed the bandwidth from 3.6 to 10GHz with the 20dB outband rejection. For the U.S. UWB band design, the matching line was inserted between the two parallel-coupled lines. The matching at both band edges was then qualitatively analyzed on the smithchart. The HFSS simulation results of the structure realized the bandwidth from 3.1 to 10.6GHz with sharp attenuation slope characteristics for SWR < 2.0. The measurement results agree well with the simulation results.

Yasuzumi, Takenori; Omote, Yusuke; Uwano, Tomoki; Hashimoto, Osamu

176

Compact band-notched UWB printed square-ring monopole antenna  

Microsoft Academic Search

A simple and compact ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed in this paper. The antenna is partially grounded so that the Q value is depressed and the impedance bandwidth is broadened. A small strip bar is loaded at the centre of the square ring radiator and the impedance bandwidth of the antenna overlapped with IEEE

Hongwei Deng; Xiaoxiang He; Binyan Yao; Yonggang Zhou

2008-01-01

177

Feasibility study into the identification of landmines using UWB radar: an analysis using synthesized data  

Microsoft Academic Search

The goal of this research is to detect and identify buried land mines (LM). The technique being investigated is the use of ultra-wideband (100 MHz to 3 GHz) ground penetrating radar (UWB\\/GPR). The first step is to gain an understanding of the scattered signal received from the use of such a system. A major point of interest is: which electromagnetic

J. LoVetri; S. Primak; B. J. A. M. van Leersum; A. P. M. Zwamborn

1998-01-01

178

Accuracy Enhancement of UWB Indoor Localization System via Arrangement of Base Stations  

Microsoft Academic Search

An ultra wideband (UWB) 3D positioning radar system with mm-range accuracy has been developed. The accuracy can be further improved by increasing the number of base station (BS). Also the space distribution of the base stations will greatly affect the accuracy of the localization system. In this paper, accuracy enhancement for 3D indoor localization has been demonstrated with the use

Cemin Zhang; Michael Kuhn; Brandon Merkl; Aly E. Fathy; Mohamed Mahfouz

179

Physical optics characterization of a THz time domain system: UWB leaky lens antenna vs. Austin switch  

Microsoft Academic Search

In this work we show that a THz time domain system based on photoconductive antennas can be improved by over one order of magnitude by using the Ultra-wideband (UWB) leaky lens antenna. The system has been analyzed by implementing a physical optics method to characterize radiated fields by a silicon lens.

N. Llombart; A. Neto; P. H. Siegel

2010-01-01

180

Modeling of the TOA-based distance measurement error using UWB indoor radio measurements  

Microsoft Academic Search

Time of arrival (TOA) estimation used with ultra wideband (UWB) transmission is currently the most popular technique for accurate indoor geolocation. Due to severe indoor multipath conditions, these techniques often suffer from significant inaccuracy in location estimation. In this paper, we introduce a model for the error in estimated distance as measured from the estimated TOA of the direct path

Bardia Alavi; Kaveh Pahlavan

2006-01-01

181

Enhanced-accuracy channel estimation and ranging for IR-UWB energy detectors  

Microsoft Academic Search

The high temporal resolution of impulse radio ultra wideband (IR-UWB) communication systems makes these systems capable of obtaining high accuracies in ranging and channel estimation. At the same time, the required sampling rates and the associated complexity often prohibit the use of conventional digital (coherent) receivers. The energy detector, a non-coherent receiver, employs low sampling rates but suffers from reduced

Bernhard C. Geiger; Thomas Gigl; Klaus Witrisal

2010-01-01

182

UWB Tracking Software Development  

NASA Technical Reports Server (NTRS)

An Ultra-Wideband (UWB) two-cluster Angle of Arrival (AOA) tracking prototype system is currently being developed and tested at NASA Johnson Space Center for space exploration applications. This talk discusses the software development efforts for this UWB two-cluster AOA tracking system. The role the software plays in this system is to take waveform data from two UWB radio receivers as an input, feed this input into an AOA tracking algorithm, and generate the target position as an output. The architecture of the software (Input/Output Interface and Algorithm Core) will be introduced in this talk. The development of this software has three phases. In Phase I, the software is mostly Matlab driven and calls C++ socket functions to provide the communication links to the radios. This is beneficial in the early stage when it is necessary to frequently test changes in the algorithm. Phase II of the development is to have the software mostly C++ driven and call a Matlab function for the AOA tracking algorithm. This is beneficial in order to send the tracking results to other systems and also to improve the tracking update rate of the system. The third phase is part of future work and is to have the software completely C++ driven with a graphics user interface. This software design enables the fine resolution tracking of the UWB two-cluster AOA tracking system.

Gross, Julia; Arndt, Dickey; Ngo, Phong; Phan, Chau; Dusl, John; Ni, Jianjun; Rafford, Melinda

2006-01-01

183

Low-power sliding correlation CMOS UWB pulsed Radar receiver for motion detection  

Microsoft Academic Search

This paper presents a low-power coherent receiver for UWB pulsed radar for motion detection. Due to accuracy of the radar motion detection, coherent detection scheme is adopted in the receiver. To relax the stringent requirement of timing synchronization, sliding correlation detection is proposed. The clocking step which determines detection resolution is determined by 2 ns which is half of a

Anh Tuan Phan; Ronan Farrell; Min-Suk Kang; Seok-Kyun Han; Sang-Gug Lee

2009-01-01

184

An ultra-wideband surface plasmonic filter in microwave frequency  

NASA Astrophysics Data System (ADS)

We propose an ultra-wideband plasmonic waveguide based on designer surface plasmon polaritons (DSPPs) with double gratings. In such plasmonic metamaterials, the DSPP waves in the region of lower frequencies of the dispersion curve can be tightly confined and hence effectively broaden the operating bandwidth. Based on such features, we design and fabricate a high performance DSPP filter, in which a transducer consisting of microstrip, slotline, and gradient corrugations is employed to feed electromagnetic energies into the plasmonic waveguide with high efficiency. The simulated and measured results on reflection and transmission coefficients in the microwave frequency demonstrate the excellent filtering characteristics such as low loss, wide band, and high square ratio. The high performance DSPP waveguide and filter pave a way to develop advanced plasmonic integrated functional devices and circuits in the microwave and terahertz frequencies.

Gao, Xi; Zhou, Liang; Liao, Zhen; Ma, Hui Feng; Cui, Tie Jun

2014-05-01

185

IMPLEMENTATION OF FAST FOCUSING ALGORITHM FOR UWB STEPPED FREQUENCY GPR SAR IMAGING  

Microsoft Academic Search

This paper discusses a fast and efficient focusing algorithm for ultra wideband (UWB) stepped-frequency continuous- wave (SFCW) side-looking SAR image formation. Conventional SFCW SAR focusing algorithms are mostly based on the matched filter concept. Their frequency-domain implementation is burdensome. In this paper we present a more rapid and efficient algorithm for real-time and automatic UWB SFCW SAR imaging, especially for

B. Sai; J. J. M. de Wit; L. P. Ligthart

186

Comparative analysis of UWB deconvolution and feature-extraction algorithms for GPR landmine detection  

Microsoft Academic Search

In this work we developed target recognition algorithms for landmine detection with ultra-wideband ground penetrating radar (UWB GPR). Due to non-stationarity of UWB signals their processing requires advanced techniques, namely regularized deconvolution, time-frequency or time-scale analysis. We use deconvolution to remove GPR and soil characteristics from the received signals. An efficient algorithm of deconvolution, based on a regularized Wiener inverse

Timofei G. Savelyev; Motoyuki Sato

2004-01-01

187

Performance Evaluation for UWB Signal Transmissions in the Distributed Multi-Cell Environment Using ROF Technology  

Microsoft Academic Search

We estimate the performance of ultra-wideband (UWB) signal transmissions for a multi-cell environment combined with a large virtual cell using radio-over-fiber (ROF) technologies. For a large virtual cell, UWB signal transmissions have been evaluated in the overlapped area between cells using a realistic channel model based on a modified ? – k model. The effects of multipath interference and delay

Yonghoon Kim; Sangil Kim; Hodeok Jang; Sub Hur; Jaehoon Lee; Jichai Jeong

2005-01-01

188

Ultra-wideband Radar Methods and Techniques of Medical Sensing and Imaging  

SciTech Connect

Ultra-wideband radar holds great promise for a variety of medical applications. We have demonstrated the feasibility of using ultra-wideband sensors for detection of internal injuries, monitoring of respiratory and cardiac functions, and continuous non-contact imaging of the human body. Sensors are low-power, portable, and do not require physical contact with the patient. They are ideal for use by emergency responders to make rapid diagnosis and triage decisions. In the hospital, vital signs monitoring and imaging application could improve patient outcomes. In this paper we present an overview of ultra-wideband radar technology, discuss key design tradeoffs, and give examples of ongoing research in applying ultra-wideband technology to the medical field.

Paulson, C N; Chang, J T; Romero, C E; Watson, J; Pearce, F J; Levin, N

2005-10-07

189

Ultra-Wideband Tapered Slot Antenna Arrays with Parallel-Plate Waveguides  

Microsoft Academic Search

Owing to their ultra-wideband characteristics, tapered slot antennas (TSAs) are used as element antennas in wideband phased arrays. However, when the size of a TSA is reduced in order to prevent the generation of a grating lobe during wide-angle beam scanning, the original ultra-wideband characteristics are degraded because of increased reflections from the ends of the tapered slot aperture. To

Satoshi Yamaguchi; Hiroaki Miyashita; Toru Takahashi; Masataka Otsuka; Yoshihiko Konishi

2010-01-01

190

CPW-Fed UWB slot antenna with band notched design  

Microsoft Academic Search

A compact coplanar waveguide (CPW) fed slot antenna developed for ultra wideband (UWB) applications with notched band ranging from 5.1 GHz to 5.9 GHz is presented. By inserting a rectangular slot in the ground plane a notching in the particular band can be achieved. The characteristics of the designed structure are investigated by using MoM based electromagnetic solver, IE3D. The

J. William; R. Nakkeeran

2009-01-01

191

Localization and Communication for UWB-based Wireless Sensor Networks  

Microsoft Academic Search

The great demand for location-aware wireless sensor networks (WSNs) motivates the research in this thesis. The unique characteristics of WSNs impose numerous challenges on localization and communication. In this thesis, we handle some key challenges and provide affordable solutions.\\u000a\\u000aImpulse radio ultra wideband (IR-UWB) is employed as the fundamental technology for both localization and communication due to its distinctive advantages

Y. Wang

2011-01-01

192

UWB On-Body Radio Channel Modelling Using  

Microsoft Academic Search

This paper presents the ultra-wideband (UWB) on- body radio channel modelling using a sub-band Finite-Difference Time-Domain (FDTD) method and a model combining the uniform geometrical theory of diffraction (UTD) and ray tracing (RT). In the sub-band FDTD model, the frequency band (3 - 9 GHz) is uniformly divided into 12 sub-bands in order to take into account the material frequency

Yan Zhao; Yang Hao; Akram Alomainy; Clive Parini

193

DOA Estimation of EM Pulses Emitted from Lightning Discharges  

NASA Astrophysics Data System (ADS)

We propose an improved direction-of-arrival estimation technique for ultra-wideband (UWB) electromagnetic waves, which allows for the effect of the antenna mutual coupling. This technique is comprised of a UWB interferometry, a Root-MUSIC, and a database. The effectiveness of our scheme is demonstrated through a numerical example.

Hirata, Akimasa; Morimoto, Takeshi; Kawasaki, Zen-Ichiro

194

UWB Tracking System Design for Free-Flyers  

NASA Technical Reports Server (NTRS)

This paper discusses an ultra-wideband (UWB) tracking system design effort for Mini-AERCam (Autonomous Extra-vehicular Robotic Camera), a free-flying video camera system under development at NASA Johnson Space Center for aid in surveillance around the International Space Station (ISS). UWB technology is exploited to implement the tracking system due to its properties, such as high data rate, fine time resolution, and low power spectral density. A system design using commercially available UWB products is proposed. A tracking algorithm TDOA (Time Difference of Arrival) that operates cooperatively with the UWB system is developed in this research effort. Matlab simulations show that the tracking algorithm can achieve fine tracking resolution with low noise TDOA data. Lab experiments demonstrate the UWB tracking capability with fine resolution.

Ni, Jianjun; Arndt, Dickey; Phan, Chan; Ngo, Phong; Gross, Julia; Dusl, John

2004-01-01

195

Capacitive-Ended Interdigital Coupled Lines for UWB Bandpass Filters With Improved Out-of-Band Performances  

Microsoft Academic Search

This letter presents a novel ultra-wideband (UWB) microstrip bandpass filter on a microstrip line with improved out-of-band performances. A multiple-mode resonator (MMR) is first constituted to equally allocate its first three resonant frequencies in the 3.1-10.6-GHz UWB band. Two capacitive-ended interdigital coupled lines are then formed to assign their transmission zero towards the fourth-order resonant frequency of this MMR, thereby

Sheng Sun; Lei Zhu

2006-01-01

196

The GIMLI: A Compact High-Power UWB Radiation Source  

NASA Astrophysics Data System (ADS)

This chapter presents the design and performances of a compact, general-purpose, high-power ultra-wideband (UWB) source named GIMLI. The system was designed for dual use, homeland security and military applications. It is powered by a compact, coaxial 12-stage Marx generator with a rise time lower than 25 ns and an operating voltage up to 360 kV. A fast monocycle pulse is sharpened using a pulse former (MPF). The shaper stage comprises a switching module including a peaking and a grounding multi-channel spark gap under a N2 pressure of 6 MPa. The module is followed by a monopulse-to-monocycle converter based on a coaxial Blumlein pulse forming line. The bipolar signal measured at the output of the MPF has a duration shorter than 2 ns with a rise time of 250 ps. The peak-to-peak output voltage is 250 kV on a 50 ? resistive load. Repetitive operation of the MPF has been experienced with a 200 Hz Tesla transformer developed by the CEA (Commissariat à l'Energie Atomique). Electromagnetic energy is focused by a dedicated antenna. The designed antenna is a TEM half-horn with two ridges which improve the low-frequency focusing. High-power radiation tests show that the field measured at a distance of 9 m from the TEM Horn-antenna is higher than 120 kV/m.

Delmote, P.; Martin, B.

197

Ultra-Wideband Optical Modulation Spectrometer (OMS) Development  

NASA Technical Reports Server (NTRS)

The optical modulation spectrometer (OMS) is a novel, highly efficient, low mass backend for heterodyne receiver systems. Current and future heterodyne receiver systems operating at frequencies up to a few THz require broadband spectrometer backends to achieve spectral resolutions of R approximately 10(exp 5) to 10(exp 6) to carry out many important astronomical investigations. Among these are observations of broad emission and absorption lines from extra-galactic objects at high redshifts, spectral line surveys, and observations of planetary atmospheres. Many of these lines are pressure or velocity broadened with either large half-widths or line wings extending over several GHz. Current backend systems can cover the needed bandwidth only by combining the output of several spectrometers, each with typically up to 1 GHz bandwidth, or by combining several frequency-shifted spectra taken with a single spectrometer. An ultra-wideband optical modulation spectrometer with 10 - 40 GHz bandwidth will enable broadband ob- servations without the limitations and disadvantages of hybrid spectrometers. Spectrometers like the OMS will be important for both ground-based observatories and future space missions like the Single Aperture Far-Infrared Telescope (SAFIR) which might carry IR/submm array heterodyne receiver systems requiring a spectrometer for each array pixel. Small size, low mass and small power consumption are extremely important for space missions. This report summarizes the specifications developed for the OMS and lists already identified commercial parts. The report starts with a review of the principle of operation, then describes the most important components and their specifications which were derived from theory, and finishes with a conclusion and outlook.

Gardner, Jonathan (Technical Monitor); Tolls, Volker

2004-01-01

198

UWB Technology and Applications on Space Exploration  

NASA Technical Reports Server (NTRS)

Ultra-wideband (UWB), also known as impulse or carrier-free radio technology, is one promising new technology. In February 2002, the Federal Communications Commission (FCC) approved the deployment of this technology. It is increasingly recognized that UWB technology holds great potential to provide significant benefits in many terrestrial and space applications such as precise positioning/tracking and high data rate mobile wireless communications. This talk presents an introduction to UWB technology and some applications on space exploration. UWB is characterized by several uniquely attractive features, such as low impact on other RF systems due to its extremely low power spectral densities, immunity to interference from narrow band RF systems due to its ultra-wide bandwidth, multipath immunity to fading due to ample multipath diversity, capable of precise positioning due to fine time resolution, capable of high data rate multi-channel performance. The related FCC regulations, IEEE standardization efforts and industry activities also will be addressed in this talk. For space applications, some projects currently under development at NASA Johnson Space Center will be introduced. These include the UWB integrated communication and tracking system for Lunar/Mars rover and astronauts, UWB-RFID ISS inventory tracking, and UWB-TDOA close-in high resolution tracking for potential applications on robonaut.

Ngo, Phong; Phan, Chau; Gross, Julia; Dusl, John; Ni, Jianjun; Rafford, Melinda

2006-01-01

199

FPGA based Ultra-Wideband pseudo-noise radar  

Microsoft Academic Search

A high accuracy experimental platform for Ultra Wide Band (UWB) PN radar performance evaluation has been created. This PN radar platform could be used for the applications such as unmanned- aerial-vehicle anti-collision and short-range distance measurement etc (3). It includes compact size X-band radar transceiver, baseband signal processing in FPGA, high speed analog to digital converter (ADC), and Matlab tools.

Amutha Jayakumar; Asha Durafe

2011-01-01

200

UWB micro-doppler radar for human gait analysis using joint range-time-frequency representation  

NASA Astrophysics Data System (ADS)

In this paper, we present a novel, standalone ultra wideband (UWB) micro-Doppler radar sensor that goes beyond simple range or micro-Doppler detection to combined range-time-Doppler frequency analysis. Moreover, it can monitor more than one human object in both line-of-sight (LOS) and through wall scenarios, thus have full human objects tracking capabilities. The unique radar design is based on narrow pulse transceiver, high speed data acquisition module, and wideband antenna array. For advanced radar post-data processing, joint range-time-frequency representation has been performed. Characteristics of human walking activity have been analyzed using the radar sensor by precisely tracking the radar object and acquiring range-time-Doppler information simultaneously. The UWB micro-Doppler radar prototype is capable of detecting Doppler frequency range from -180 Hz to +180 Hz, which allows a maximum target velocity of 9 m/s. The developed radar sensor can also be extended for many other applications, such as respiration and heartbeat detection of trapped survivors under building debris.

Wang, Yazhou; Fathy, Aly E.

2013-05-01

201

Characterization of local 3D rough surfaces using UWB near-range phase-based GPR signatures from wide-beamwidth antennas  

Microsoft Academic Search

This paper pertains to further investigations on using an ultra wideband (UWB) multistatic coherent ground-penetrating radar (GPR) technique for precise profiling of the rough surfaces in three-dimensional space. The method is essentially based on the phase processing of the sliced layers of three-dimensional rough surfaces with multiple sub-frequency bands. The data acquired in the near range by a UWB stepped-frequency

B. Sai; L. P. Ligthart

2002-01-01

202

A 1V CMOS low-noise amplifier with inductive resonated for 3.1–10.6GHz UWB wireless receiver  

Microsoft Academic Search

In this paper a low power and low-noise amplifier (LNA) is designed for ultra-wideband (UWB) system. The design consists of a wideband input impedance matching network, two stages common-source amplifier with inductive resonated load and an output buffer for measurement purpose; it is fabricated in TSMC 0.18um standard RF CMOS process. The measured UWB LNA gives 12.0dB gain and 8.0GHz

Zhe-Yang Huang; Che-Cheng Huang; Chun-Chieh Chen; Chung-Chih Hung

2007-01-01

203

Fundamental Limits and Design Guidelines for Miniaturizing Ultra-Wideband Antennas  

Microsoft Academic Search

Fundamental physical limitations restrict an antenna's performance based on its electrical size. These fundamental limits are of the utmost importance, since the minimum size needed to achieve a particular figure of merit can be determined from them. In this paper, the physical limitations of antennas are reviewed in general, with particular emphasis on impedance matching as it relates to ultra-wideband

B. A. Kramer; C.-C. Chen; M. Lee; J. L. Volakis

2009-01-01

204

A novel pot shaped CPW-fed slot antenna for Ultra wideband applications  

Microsoft Academic Search

A novel compact Ultra wideband antenna fed by CPW is presented. The antenna has a size of 29 mm x 31 mm. The antenna is excited by Pot shaped inner tuning stub. It provides band width ranging from 2.9 GHz to 10.2 GHz which covers Ultra Wide bandwidth. The antenna can be easily integrated with radio frequency circuit for low

Akkala. Subbarao; S. Raghavan

2011-01-01

205

Model-Based Radar Power Calculations for Ultra-Wideband (UWB) Synthetic Aperture Radar (SAR).  

National Technical Information Service (NTIS)

In this study, we establish a relationship between the radar transmitted power, the target signature and the signal-to-noise ratio required for a specific target detection performance in a radar system. While this relationship can be easily derived from t...

T. Dogaru

2013-01-01

206

UWB in Millimeter Wave Band With Pulsed ILO  

Microsoft Academic Search

A simple but efficient transmitter for ultra-wide-band impulse radio wavelet generator in millimeter-wave band is presented. It is suitable for RADAR, gigabit wireless personal area network, and localization applications. This front-end involves a subharmonic injection-locked oscillator driven by a pulse generator (PG) with fast transition time (<25 ps). Its frequency oscillation is locked on one of the numerous harmonic components

Nicolas Deparis; Christophe Loyez; Nathalie Rolland; Paul-Alain Rolland

2008-01-01

207

Focus of attention in UWB SAR image  

NASA Astrophysics Data System (ADS)

The previous work demonstrate that detection based on the Laguerre transform exploits the 1D resonance response of the metallic target in the ultra wideband (UWB) synthetic aperture radar (SAR) images. The success is mainly due to the fact that Laguerre function space captures the information contained in the resonant response. However, in that case, only 1D resonance response information were utilized. In this paper, a new CFAR statistics based on spatial resonance templates is proposed. Based on the GLRT, the new CFAR statistics is formulated using the spatial extent of targets' resonance responses in the UWB SAR scenario. In the end, we show that the proposed CFAR statistics yields more robust detection.

Yen, Li-Kang; Principe, Jose C.; Fisher, John W.

1997-06-01

208

Miniature inverse parabolic step sequence damped sinusoid antenna for DS-UWB  

Microsoft Academic Search

A novel monopole antenna is proposed in this paper with 6-15 GHz bandwidth for high band Direct Sequence Ultra Wideband (DS-UWB) application. A voltage standing wave ratio (VSWR) of ?2 is achieved over the entire bandwidth. It is designed to work on a low loss duroid 5880 LZ substrate of relative permittivity 1.96 and dielectric loss tangent 0.0019. The antenna

Rashid Saleem; Anthony K. Brown

2010-01-01

209

Multiple Channel Scheduling in UWB based IEEE 802.15.3 Networks  

Microsoft Academic Search

Recent approval by the Federal Communications Commission (FCC) has led to considerable interest in exploiting ultra wideband (UWB) access on an unlicensed basis in the 3.1-10.6 GHz band. Currently, the IEEE TG802.15.3a standards group is in the process of developing an alternative high-speed link layer design conformable with the IEEE 802.15.3 wireless personal area network (WPAN) multiple access (MAC) protocol.

Aniruddha Rangnekar; Krishna M. Sivalingam

2004-01-01

210

A Novel UWB Planar Antenna with Notch Cut for Wireless Communications  

Microsoft Academic Search

\\u000a A novel printed antenna with a trimmed notch cut, fed by a simple microstrip line, is proposed and described. It is designed\\u000a and fabricated for ultra-wideband (UWB) wireless communications under the band (3.1–10.6 GHz). This antenna is composed of\\u000a a planar rectangular patch with notch cut and a transition step fed by a microstrip line with a partial ground plane. A

A. Alshehri; A. R. Sebak

2010-01-01

211

Blind Synchronization and Low-Complexity Demodulation for DS-UWB Systems  

Microsoft Academic Search

In this paper, a joint blind synchronization and demodulation scheme is developed for ultra-wideband (UWB) impulse radio systems. Based on the prior knowledge of the direct-sequence (DS) spread codes, the proposed approach can achieve frame-level synchronization with the help of frame-rate samples. Taking advantage of the periodicity of the DS spread codes, the frame-level synchronization can be carried out even

Yongwei Qiao; Tiejun Lv

2010-01-01

212

A Novel Path-Loss Model for UWB Off-Body Propagation  

Microsoft Academic Search

A novel, multi-slope dual breakpoint model for predicting path-loss in ultra-wideband (UWB) off-body communication channels, is proposed. This model is based on real-body measurements, carried out in the frequency range between 3.5GHz-6.5GHz, in an anechoic chamber. New parameters that describe this specific propagation environment are presented and evaluated. Results show that the first breakpoint point angle lies in the lit

Angelos A. Goulianos; Tim W. C. Brown; Stavros Stavrou

2008-01-01

213

Toward a Highly Accurate Ambulatory System for Clinical Gait Analysis via UWB Radios  

Microsoft Academic Search

In this paper, we propose and investigate a low-cost and low-complexity wireless ambulatory human locomotion tracking system that provides a high ranging accuracy (intersensor distance) suitable for the assessment of clinical gait analysis using wearable ultra wideband (UWB) transceivers. The system design and transceiver performance are presented in additive-white-Gaussian noise and realistic channels, using industry accepted channel models for body

Heba A. Shaban; Mohamad Abou El-Nasr; R. Michael Buehrer

2010-01-01

214

Data Detection Performance of an MTR-UWB Receiver in the Presence of Timing Errors  

Microsoft Academic Search

A multiuser transmitted-reference (MTR) ultra wideband (UWB) transceiver is recently proposed to not only increase the data transmission rate, but also enable multiple access effectively. Both features are realized by incorporating frame-rate pseudo-random sequences. This paper further studies detection performance of the MTR receiver when timing is acquired with some random errors from clock synchronization, delay estimation, etc. A timing

Brian M. Sadler; Zhengyuan Xu; Jin Tang

2005-01-01

215

Enhanced Secure Error Correction Code Schemes in Time Reversal UWB Systems  

Microsoft Academic Search

In this paper, secure channel coding schemes based on turbo codes are suggested for time reversal ultra wideband (TR-UWB)\\u000a systems. Turbo code has the capability of error correction near Shannon’s limit. Adding security to turbo code is an attractive\\u000a idea since it could reduce the overall processing cost of providing secure coded data and enjoys the advantages of high-speed\\u000a encryption

Dariush Abbasi-Moghadam; Vahid Tabataba Vakili

216

Compact CPW-fed circular slot antenna for ultra-wideband applications  

Microsoft Academic Search

A compact circular slot antenna for ultra-wideband applications is proposed in this letter. The antenna consists of a circular patch and an open annulus, and is fed by coplanar waveguide. The total dimension of the antenna is 30 mmtimes33 mmtimes1.57 mm. The proposed antenna is simulated, fabricated and tested. Results show that a maximum relative impedance bandwidth of more than

Meie Chen; Junhong Wang

2008-01-01

217

Y-Shaped Time-Domain Ultra-Wideband Antenna Array  

Microsoft Academic Search

The characteristics of a Y-shaped time-domain ultra-wideband antenna array are analyzed in this paper. The structure of the array is planar and composed of three linear arrays with constant 120-degree adjacent angle around one common endpoint. Radiation performances, including the fidelity of waveform and directional energy patterns of radiated signals can be obtained by the change of array parameters. Simulation

Jin-Ping Zhang; Yun-Sheng Xu; Wei-Dong Wang

2006-01-01

218

Timing Acquisition with Noisy Template for Ultra-Wideband Communications in Dense Multipath  

Microsoft Academic Search

Abstract— Timing acquisition is critical to enabling the potential of ultra-wideband radios in high-speed, short-range indoor wireless networking. An effective timing acquisition method should not only operate at a low sampling rate to reduce implementation complexity and synchronization time, but also be able to collect sufficient signal energy in order to operate in a reasonable transmit-SNR regime. Energy capture for

Zhi Hong Tian; Lin Wu

2005-01-01

219

Ultra-wideband, zero visual signature RF vest antenna for man-portable radios  

Microsoft Academic Search

This paper presents the recent research of the COMbat Wear INtegration (COMWIN) RF vest antenna initially presented at MILCOM2000. This version of the ultra-wideband VHF\\/UHF (30 MHz to 500 MHz) vest antenna, designated as MK-III, is integrated into the existing dismounted marine\\/soldier kevlar flak vest and has no visual signature. This antenna is one of the three COMWIN antennas developed

Jovan E. Lebaric; Richard W. Adler; Matthew E. Limbert

2001-01-01

220

On Parameter Estimation for Ultra-Wideband Channels with Clustering Phenomenon  

Microsoft Academic Search

One of the unique characteristics of ultra-wideband channels is the clustering phenomenon resolved by the ultra-wide signal bandwidth. Channel structures extended from the Saleh-Valenzuela model, e.g., the IEEE 802.15.3a and IEEE 802.15.4a models, have been proposed to describe such phenomenon. It is, however, noticed that a clear and systematic procedure to estimate the model parameters is still missing. Based on

Wei-de Wu; Chung-hsuan Wang; Chi-chao Chao; Klaus Witrisal

2008-01-01

221

Ultra-wideband ground-penetrating radar for the detection of buried metallic mines  

Microsoft Academic Search

The suitability of ultra-wideband ground-penetrating radar as a tool for the detection of buried metallic mines is explored in this paper. The analysis centers around a 200-800 MHz, dual-polarized ground penetrating radar (GPR) designed and built by SRI International. The analysis consisted of fusing the images from the dual polarizations into a single image to enhance the target objects and

S. L. Earp; E. S. Hughes; T. J. Elkins; R. Vickers

1996-01-01

222

A Frequency Triplexer for Ultra-Wideband Systems Utilizing Combined Broadside and Edge-Coupled Filters  

Microsoft Academic Search

A fully integrated triplexer for multiband ultra-wideband radio is presented. The triplexer utilizes a microstrip network and three combined broadside- and edge-coupled filters. It is fully integrated in a printed circuit board with low requirements on the printed circuit board process tolerance. Three flat subbands in the frequency band 3.1-4.8 GHz have been achieved. The group delay variation within each

Magnus Karlsson; PÄr Hakansson; Shaofang Gong

2008-01-01

223

The ultra wideband transfer function representation of complex three-dimensional electromagnetic structures  

Microsoft Academic Search

the network-oriented ultra wideband transfer function representation of complex three-dimensional elec- tromagnetic structures is investigated. The transfer function is consisting of two parts: entire function and rational or pole function. The reduction of a rank of an ill-conditioned matrix is performed in accordance with the spectral crite- rion. System identification is carried out by the Matrix Pen- cil Method (MPM)

Yury Kuznetsov; Andrey Baev; Fabio Coccetti; Peter Russer

2004-01-01

224

An ultra-wideband vertical transition from microstrip to stripline in PCB technology  

Microsoft Academic Search

An ultra-wideband transition from microstrip to stripline in PCB technology is presented applying only through via holes for simple fabrication. The design is optimized using full-wave EM simulations. A prototype is manufactured and measured achieving a return loss better than 8.7dB and an insertion loss better than 1.2 dB in the FCC frequency range. A meander-shaped delay line in stripline

Mario Leib; Michael Mirbach; Wolfgang Menzel

2010-01-01

225

Transmit Antenna Selection for Spatial Multiplexing UWB MIMO Systems Using Sorted QR Decomposition  

NASA Astrophysics Data System (ADS)

In this letter, a post-detection signal to noise ratio (SNR) is considered for transmit antenna selection, when a sorted QR decomposition (SQRD) algorithm is used for signal detection in spatial multiplexing (SM) ultra-wideband (UWB) multiple input multiple output systems. The post-detection SNR expression is obtained using a QR factorization algorithm based on a sorted Gram-Schmidt process. The employed antenna selection criterion is to utilize the largest minimum post-detection SNR value. It is shown via simulations that the antenna selection significantly enhances the BER performance of the SQRD-based SM UWB systems on a log-normal multipath fading channel.

Kim, Sangchoon

226

Ultra-Wideband Vivaldi Antenna Array for High Resolution Subsurface Imaging  

NASA Astrophysics Data System (ADS)

Use of ultra-wideband electromagnetic waves to image the subsurface yields enhanced resolution, provided sources, antennas and recording equipment can be developed and calibrated over the complete bandwidth of interest. We present a demonstration of the latest microwave transmission and recording technology to obtain high-resolution images. Our transmitter and receiver electronics are embodied in the vector network analyzer (PNA series) from Agilent, an eight-port vector network analyzer that records amplitude and phase. The analyzer is connected through a microwave multiplexer and microwave switch to an 8 element, balanced, antipodal Vivaldi antenna array, which can transmit or receive data over a bandwidth from 1.3 to 20 GHz. The bandwidth of the integrated system is determined by the bandwidth of the microwave switch, from DC to 18GHz, which interfaces the multiplexer to the PNA. The capabilities of a microwave multiplexer are employed to collect multi-channel data, by using one channel for transmission and reception on all 8 channels. The demonstration of this integrated system will be focussed on scattering from a single conducting cylinder as well as two cylinders, a dielectric and conducting cylinder, spaced at different intervals. The increased bandwidth, over that obtained in conventional GPR recording will result in pulses that have little ringing, allowing the detection of deeper reflections and eliminating any post-processing distortions that arise from deconvolving the traditional oscillatory waveform. Although the demonstration will be presented in the GHz bandwidth, suitable for imaging over a length scale to 1m, this integrated system will scale to lower bandwidths and can operate from 100 MHz to 3 GHz, with a resultant penetration depth of 10 to 20 m depending on the subsurface properties. Given the electronic constraints of the switch and the PNA, this scaling is simply achieved by enlarging the Vivaldi antenna dimensions. The advantage of using the PNA is the complete programmability, with a typical average noise level of -147 dBc and a dynamic range of 128 dB at the test-set ports. Scattering data obtained in this configuration will be imaged using time reversal techniques and an animation of a data set obtained using a previous generation of vector network analyzers will be presented. A minimum entropy stopping condition will be employed.

Yedlin, M. J.; Cresp, A.; Pichot, C.; Aliferis, I.; Dauvignac, J.; Fortino, N.; Gaffet, S.

2008-05-01

227

Capacity region of a multi-code DS-UWB system supporting variable bit rate multiclass services  

Microsoft Academic Search

An analytical formulation of the outage probability in terms of bit error rate specification for variable bit rate (VBR) multiclass services in a multi-code direct-sequence ultra-wideband (DS-UWB) system is presented. The analytical framework is formulated for the general case in which different traffic classes have different varying bit rates. Multiple spreading codes are used by each user to achieve variable

T. C. Wong; J. W. Mark; K. C. Chua

2005-01-01

228

UWB Tracking Algorithms: AOA and TDOA  

NASA Technical Reports Server (NTRS)

Ultra-Wideband (UWB) tracking prototype systems are currently under development at NASA Johnson Space Center for various applications on space exploration. For long range applications, a two-cluster Angle of Arrival (AOA) tracking method is employed for implementation of the tracking system; for close-in applications, a Time Difference of Arrival (TDOA) positioning methodology is exploited. Both AOA and TDOA are chosen to utilize the achievable fine time resolution of UWB signals. This talk presents a brief introduction to AOA and TDOA methodologies. The theoretical analysis of these two algorithms reveal the affecting parameters impact on the tracking resolution. For the AOA algorithm, simulations show that a tracking resolution less than 0.5% of the range can be achieved with the current achievable time resolution of UWB signals. For the TDOA algorithm used in close-in applications, simulations show that the (sub-inch) high tracking resolution is achieved with a chosen tracking baseline configuration. The analytical and simulated results provide insightful guidance for the UWB tracking system design.

Ni, Jianjun David; Arndt, D.; Ngo, P.; Gross, J.; Refford, Melinda

2006-01-01

229

79 GHz UWB automotive short range radar - Spectrum allocation and technology trends  

NASA Astrophysics Data System (ADS)

Automotive UWB (Ultra-Wideband) short range radar (SSR) is on the market as a key technology for novel comfort and safety systems. SiGe based 79 GHz UWB SRR will be a definite candidate for the long term substitution of the 24 GHz UWB SRR. This paper will give an overview of the finished BMBF joint project KOKON and the recently started successing project RoCC, which concentrate on the development of this technology and sensor demonstrators. In both projects, the responsibilities of Daimler AG deal with application based sensor specification, test and evaluation of realized sensor demonstrators. Recent UWB SRR frequency regulation approaches and activitites will be introduced. Furthermore, some first results of Daimler activities within RoCC will be presented, dealing with the packaging and operation of these sensors within the complex car environment.

Bloecher, H.-L.; Sailer, A.; Rollmann, G.; Dickmann, J.

2009-05-01

230

Target material characterization using high-order signal processing of ultra-wideband radar data  

Microsoft Academic Search

Results obtained by two high-order signal processing methods applied to ultrawideband (UWB) radar data in the UHF band are described. The UWB radar data were collected in a specially designed bistatic test range. Four types of UWB signals were used to test a metal (reference) plate, five different commercially available radar absorbing material samples with metal backing, and five natural

Vasilis Z. Marmarelis; David Sheby; Elizabeth C. Kisenwether; Todd A. Erdley

1992-01-01

231

EMI issues in UWB systems  

Microsoft Academic Search

Recent advances in microcircuits and other technologies have resulted in the development of pulsed radar and communications systems with very narrow pulse widths and ultra wide bandwidths. These UWB devices can perform a number of useful radar and communication functions that make them very appealing for both commercial and military applications. UWB Systems are characterized by having either a large

B. Sreedevi

2006-01-01

232

DC-offset effect cancelation method using mean-padding FFT for automotive UWB radar sensor  

NASA Astrophysics Data System (ADS)

To improve road safety and realize intelligent transportation, Ultra-Wideband (UWB) radars sensor in the 24 GHz domain are currently under development for many automotive applications. Automotive UWB radar sensor must be small, require low power and inexpensive. By employing a direct conversion receiver, automotive UWB radar sensor is able to meet size and cost reduction requirements. We developed Automotive UWB radar sensor for automotive applications. The developed receiver of the automotive radar sensor is direct conversion architecture. Direct conversion architecture poses a dc-offset problem. In automotive UWB radar, Doppler frequency is used to extract velocity. The Doppler frequency of a vehicle can be detected using zero-padding Fast Fourier Transform (FFT). However, a zero-padding FFT error is occurs due to DC-offset problem in automotive UWB radar sensor using a direct conversion receiver. Therefore, dc-offset problem corrupts velocity ambiguity. In this paper we proposed a mean-padding method to reduce zero-padding FFT error due to DC-offset in automotive UWB radar using direct conversion receiver, and verify our proposed method with computer simulation and experiment using developed automotive UWB radar sensor. We present the simulation results and experiment result to compare velocity measurement probability of the zero-padding FFT and the mean-padding FFT. The proposed algorithm simulated using Matlab and experimented using designed the automotive UWB radar sensor in a real road environment. The proposed method improved velocity measurement probability.

Ju, Yeonghwan; Kim, Sang-Dong; Lee, Jong-Hun

2011-05-01

233

Ultra-Wideband GPR Imaging of the Vaucluse Karst Aquifer  

NASA Astrophysics Data System (ADS)

In this paper, we present the validation of an Ultra Wide band measurement system which is the first experimental step of the French MAXWELL Research Project devoted to the survey of the karst aquifer located in the Vaucluse in Provence. This radar system employs Exponentially Tapered Slot Antennas (ETSA), with a usable bandwidth from 100 MHz to 2.5 GHz. The antenna is driven by a .01- 26.5 GHz Agilent vector network analyzer (VNA), with a noise floor of -120dB under test conditions and a noise floor of -100 dB in a field setting. A synthetic pulse is applied to the antenna by using a classical step frequency sweeping. The recorded amplitudes and phases of the reflection coefficient (S11 parameter) are filtered and inverse Fourier transformed to obtain the time-domain data. In principal, due to the flat radiation characteristic of the frequency generator, appropriate synthetic pulses can be generated for analysis. The advantages of this approach are mainly, 1) a large depth resolution due to increased bandwidth, 2) a wider dynamic range for detection of weak late underground echoes, 3) a low signal distortion due to absence of pulse deconvolution post-processing. The foregoing system was deployed inside a tunnel in the Low-Noise Underground Laboratory (LSBB) located in Rustrel (France) which allows the use of low power radiation. Minimization of noise interference was accomplished by : 1) using low noise and low-loss cables, 2) using a PVC structure covered with absorbers to shield the ETSA from unwanted tunnel wall reflections and from radiation from the vector network analyzer, 3) an effective calibration of long cables to the antenna connector with careful cable unwinding to reduce phase errors, 4) a power level fixed at 8 dBm in the frequency band of interest to avoid distortion in the mixer of the VNA. Monostatic or multistatic data, were collected by moving manually the antennas along the PVC frame, in 5 cm increments over a length of 6 m. Both parallel and perpendicular polarizations were recorded. Data were obtained from 150 MHz to 2 GHz to reduce any reflections from the connection to the analyzer. Time sections were then processed after an inverse Fourier transform. To validate our results (from a geophysics point of view), reference data were also collected using 100, 250 and 500 MHz RAMAC GPR systems. Results are very promising especially regarding the resolution of the images, depth penetration and low emitting power. In future experiments, our approach could be still improved by using shorter cables, high directive antennas and absorbers to reduce coupling in multistatic configurations.

Dauvignac, J.; Fortino, N.; Sénéchal, G.; Cresp, A.; Yedlin, M.; Gaffet, S.; Rousset, D.; Pichot, C.

2008-12-01

234

UWB Tracking System Design with TDOA Algorithm  

NASA Technical Reports Server (NTRS)

This presentation discusses an ultra-wideband (UWB) tracking system design effort using a tracking algorithm TDOA (Time Difference of Arrival). UWB technology is exploited to implement the tracking system due to its properties, such as high data rate, fine time resolution, and low power spectral density. A system design using commercially available UWB products is proposed. A two-stage weighted least square method is chosen to solve the TDOA non-linear equations. Matlab simulations in both two-dimensional space and three-dimensional space show that the tracking algorithm can achieve fine tracking resolution with low noise TDOA data. The error analysis reveals various ways to improve the tracking resolution. Lab experiments demonstrate the UWBTDOA tracking capability with fine resolution. This research effort is motivated by a prototype development project Mini-AERCam (Autonomous Extra-vehicular Robotic Camera), a free-flying video camera system under development at NASA Johnson Space Center for aid in surveillance around the International Space Station (ISS).

Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Phan, Chau; Gross, Julia; Dusl, John; Schwing, Alan

2006-01-01

235

S – C – L triple wavelength superluminescent source based on an ultra-wideband SOA and FBGs  

NASA Astrophysics Data System (ADS)

We propose and demonstrate a wide-band semiconductor optical amplifier (SOA) based triple-wavelength superluminescent source with the output in the S-, C- and L-band regions. The proposed systems uses an ultra-wideband SOA with an amplification range from 1440 to 1620 nm as the linear gain medium. Three fibre Bragg gratings (FBGs) with centre wavelengths of 1500, 1540 and 1580 nm are used to generate the lasing wavelengths in the S-, Cand L-bands respectively, while a variable optical attenuator is used to finely balance the optical powers of the lasing wavelengths. The ultra-wideband SOA generates an amplified spontaneous emission (ASE) spectrum with a peak power of -33 dBm at the highest SOA drive current, and also demonstrates a down-shift in the centre wavelength of the generated spectrum due to the spatial distribution of the carrier densities. The S-band wavelength is the dominant wavelength at high drive currents, with an output power of -6 dBm as compared to the C- and L-bands, which only have powers of -11 and -10 dBm, respectively. All wavelengths have a high average signal-to-noise ratio more than 60 dB at the highest drive current of 390 mA, and the system also shows a high degree of stability, with power fluctuations of less than 3 dB within 70 min. The proposed system can find many applications where a wide-band and stable laser source is crucial, such as in communications and sensing.

Ahmad, H.; Zulkifli, M. Z.; Hassan, N. A.; Muhammad, F. D.; Harun, S. W.

2013-10-01

236

Single-element based ultra-wideband antenna array concepts for wireless high-precision 2-D local positioning  

NASA Astrophysics Data System (ADS)

We generally categorize the approaches for ultra-wideband antenna array design, and consequently propose simplified concepts for antenna arrays for a high-precision, ultra-wideband FMCW radar 2-D local positioning system to obtain robustness against multi path interference, perform angle of arrival analysis, as well as instantaneous heading estimation. We focus on low-cost and mechanical robust, industrial-application ready antennas. The antenna arrays are optimized for operation in the 5 GHz to 8 GHz frequency range and are designed towards supporting full omnidirectional 360° as well as partial half-plane direction of arrival estimation. Two different concepts for vehicle- as well as wall-mounted antenna array systems are proposed and discussed. We propose a wideband unidirectional bow-tie antenna array element having 97% impedance and 37% pattern bandwidth and a robust vehicle mounted omnidirectional antenna element having more than 85% impedance and pattern bandwidth.

Gardill, M.; Fischer, G.; Weigel, R.; Koelpin, A.

2013-07-01

237

UWB Tracking System Design for Lunar/Mars Exploration  

NASA Technical Reports Server (NTRS)

This paper describes a design effort for a prototype ultra-wideband (UWB) tracking system that is currently under development at NASA Johnson Space Center (JSC). The system is being studied for use in tracking of lunar/Mars rovers during early exploration missions when satellite navigation systems are not available. The UWB technology is exploited to implement the tracking system due to its properties such as high data rate, fine time resolution, low power spectral density, and multipath immunity. A two-cluster prototype design using commercially available UWB products is proposed to implement the Angle Of Arrival (AOA) tracking methodology in this research effort. An AOA technique using the Time Difference Of Arrival (TDOA) information is utilized for location estimation in the prototype system, not only to exploit the precise time resolution possible with UWB signals, but also to eliminate the need for synchronization between the transmitter and the receiver. After the UWB radio at each cluster is used to obtain the TDOA estimates from the UWB signal sent from the target, the TDOA data is converted to AOA data to find the angle of arrival, assuming this is a far field application. Since the distance between two clusters is known, the target position is computed by a simple triangulation. Simulations show that the average tracking error at a range of 610 meters is 2.7595 meters, less than 0.5% of the tracking range. Outdoor tests to track the SCOUT vehicle (The Science Crew Operations and Utility Testbed) near the Meteor Crater, Flagstaff, Arizona were performed on September 12-13, 2005. The tracking performance was obtained with less than 1% tracking error at ranges up to 2000 feet. No RF interference with on-board GPS, video, voice and telemetry systems was detected. Outdoor tests demonstrated the UWB tracking capability.

Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Phan, Chau; Gross, Julia

2006-01-01

238

An Electronic Circuit System for Time-Reversal of Ultra-Wideband Short Impulses Based on Frequency-Domain Approach  

Microsoft Academic Search

In this paper, a compact and low-cost electronic circuit system is designed for time-reversal of ultra-wideband short impulses (with nanosecond and sub-nanosecond temporal durations). A frequency-domain approach is adopted to avoid high sampling rate in time. Specifically, the proposed system obtains the discrete spectra of input impulses first; then realizes time-reversal in frequency domain; and finally synthesizes the time-reversed impulses

Huiqing Zhai; Shaoshu Sha; Varun K. Shenoy; Sungyong Jung; Mingyu Lu; Kyoungwon Min; Sungchul Lee; Dong S. Ha

2010-01-01

239

Preliminary field results of an ultra-wideband (10-620 MHz) stepped-frequency ground penetrating radar  

Microsoft Academic Search

The authors present the results from preliminary field trials using a newly developed ultra-wideband, stepped-frequency ground penetrating radar system. This system has been developed to improve the maximum penetration depth capability in ground penetrating radar (GPR) applications without degradation of resolving power. To achieve this, they have based their system on the stepped-frequency radar technique operating across the 10-620 MHz

G. F. Stickley; D. A. Noon; M. Chernlakov; I. D. Longstaff

1997-01-01

240

Simulation of an ultra-wideband antenna for step-frequency ground penetrating radar using method of moments  

Microsoft Academic Search

Presented in this paper are the results of simulation of ultra-wideband antennas for step-frequency ground penetrating radar (GPR) using IE3D software realizing method of moments. Features of planar antenna currents distribution, influencing on radiations parameters are discussed. Ways of improvement of antenna characteristics accounting for the features of the antenna utilization are proposed. The simulation data for planar tapered slot

Ye. Maksimovitch; V. Mikhnev; P. Vainikainen

2005-01-01

241

Ultra-wideband time-delay line inspired by composite right\\/left-handed transmission line unit cell  

Microsoft Academic Search

This paper presents a design of ultra-wideband time-delay line inspired by the composite right\\/left-handed transmission line (CRLH TL) unit cell. A rotated version of the conventional CRLH TL unit cell is used to increase the operating bandwidth. The time-delay line is optimized using computer simulation and then fabricated on a PCB for measurement. For comparison, the time-delay lines using the

J. Zhang; S. W. Cheung; T. I. Yuk

2010-01-01

242

Time-Reversal Based Range Extension Technique for Ultra-Wideband (UWB) Sensors and Applications in Tactical Communications and Networking.  

National Technical Information Service (NTIS)

This technical report (quarterly) details the work for Office of Naval Research (ONR) by Tennessee Tech. The goal of this project jointly funded by ONR, NSF, and ARO is to build a general purpose testbed with time reversal capability at the transmitter si...

N. Guo P. Zhang R. C. Qiu Y. Song Z. Hu

2008-01-01

243

Self organization of wireless sensor networks using ultra-wideband radios  

DOEpatents

A novel UWB communications method and system that provides self-organization for wireless sensor networks is introduced. The self-organization is in terms of scalability, power conservation, channel estimation, and node synchronization in wireless sensor networks. The UWB receiver in the present invention adds two new tasks to conventional TR receivers. The two additional units are SNR enhancing unit and timing acquisition and tracking unit.

Dowla, Farid U. (Castro Valley, CA); Nekoogar, Franak (San Ramon, CA); Spiridon, Alex (Palo Alto, CA)

2009-06-16

244

UWB communication receiver feedback loop  

DOEpatents

A novel technique and structure that maximizes the extraction of information from reference pulses for UWB-TR receivers is introduced. The scheme efficiently processes an incoming signal to suppress different types of UWB as well as non-UWB interference prior to signal detection. Such a method and system adds a feedback loop mechanism to enhance the signal-to-noise ratio of reference pulses in a conventional TR receiver. Moreover, sampling the second order statistical function such as, for example, the autocorrelation function (ACF) of the received signal and matching it to the ACF samples of the original pulses for each transmitted bit provides a more robust UWB communications method and system in the presence of channel distortions.

Spiridon, Alex (Palo Alto, CA); Benzel, Dave (Livermore, CA); Dowla, Farid U. (Castro Valley, CA); Nekoogar, Faranak (San Ramon, CA); Rosenbury, Erwin T. (Castro Valley, CA)

2007-12-04

245

Accurate Permittivity Measurements for Microwave Imaging via Ultra-Wideband Removal of Spurious Reflectors  

PubMed Central

The use of microwave imaging is becoming more prevalent for detection of interior hidden defects in manufactured and packaged materials. In applications for detection of hidden moisture, microwave tomography can be used to image the material and then perform an inverse calculation to derive an estimate of the variability of the hidden material, such internal moisture, thereby alerting personnel to damaging levels of the hidden moisture before material degradation occurs. One impediment to this type of imaging occurs with nearby objects create strong reflections that create destructive and constructive interference, at the receiver, as the material is conveyed past the imaging antenna array. In an effort to remove the influence of the reflectors, such as metal bale ties, research was conducted to develop an algorithm for removal of the influence of the local proximity reflectors from the microwave images. This research effort produced a technique, based upon the use of ultra-wideband signals, for the removal of spurious reflections created by local proximity reflectors. This improvement enables accurate microwave measurements of moisture in such products as cotton bales, as well as other physical properties such as density or material composition. The proposed algorithm was shown to reduce errors by a 4:1 ratio and is an enabling technology for imaging applications in the presence of metal bale ties.

Pelletier, Mathew G.; Viera, Joseph A.; Wanjura, John; Holt, Greg

2010-01-01

246

A Reconfigurable, 130 nm CMOS 108 pJ\\/pulse, Fully Integrated IR-UWB Receiver for Communication and Precise Ranging  

Microsoft Academic Search

This paper presents a fully integrated flexible ultra-low power UWB impulse radio receiver, capable of cm-accurate ranging. Ultra-low-power consumption is achieved by employing the quadrature analog correlating receiver architecture, by exploiting the duty-cycled nature of the system, by operating in the sub-1 GHz band as well as by careful circuit design. Two pulse rates, 39.0625 Mpulses per second (Mpps) and

Nick Van Helleputte; Marian Verhelst; Wim Dehaene; Georges Gielen

2010-01-01

247

A Flexible, Ultra-Low-Energy 35 pJ\\/Pulse Digital Back-End for a QAC IR-UWB Receiver  

Microsoft Academic Search

A low-energy, flexible digital back-end for the quadrature analog correlating (QAC) IR-UWB receiver, implemented in 0.13 m CMOS technology, is presented. The built-in flexibility allows the receiver to operate over a wide range of frequency bands, pulse rates, code lengths, acquisition modes, etc. This ability to dynamically trade power consumption, system performance and system reliability is crucial for application in

Marian Verhelst; Wim Dehaene

2008-01-01

248

Error Analysis of Hybrid DS-Multiband-UWB Multiple Access System in the Presence of Narrowband Interference  

NASA Astrophysics Data System (ADS)

This paper proposes a hybrid multiband (MB) ultra wideband (UWB) system with direct sequence (DS) spreading. The theoretical error analysis for the DS-MB-UWB multiple access system with Rake receiver in the presence of multipath and narrowband interference is developed. The developed theoretical framework models the multiple access interference (MAI), multipath interference (MI) and narrowband interference for the designed UWB system. It is shown that the system error performance corresponding to the combining effects of these interference can be accurately modeled and calculated. Monte Carlo simulation results are provided to validate the accuracy of the model. Additionally, it is found that narrowband interference can be mitigated effectively in the multiband UWB system by suppressing the particular UWB sub-band co-existing with the interfering narrowband signal. A typical improvement of 5dB can be achieved with 75% sub-band power suppression. On the other hand, suppression of UWB sub-band is also found to decrease frequency diversity, thus facilitating the increase of MAI. In this paper, the developed model is utilized to determine the parameters that optimize the UWB system performance by minimizing the effective interference.

Sum, Chin-Sean; Rahman, Mohammad Azizur; Sasaki, Shigenobu; Harada, Hiroshi; Kato, Shuzo

249

Novel Dual-band Slot Antenna Design for Bluetooth and UWB Applications  

NASA Astrophysics Data System (ADS)

A novel technique to introduce an additional low frequency band to compact ultra wideband (UWB) slot antennas is proposed in this paper. To get an additional Bluetooth band, a parasitic strip is mounted on the back side of the slot edge. Because of the interaction of the strip and the slot edge, the Bluetooth band can be obtained while a notch band between the Bluetooth band and UWB band also appears. Two types of feeding, coplanar waveguide and microstrip line, are investigated. The proposed antennas are both fabricated on a low-cost FR4 substrate and have compact size (24 mm × 28 mm × 1 mm). The good agreement between measured and simulated results verifies our design.

Huang, Hai-Yan; Shao, Wei; Wang, Bing-Zhong; Ma, Xiao-Liang

2014-05-01

250

Improving Performance of SC-UWB Systems with the Optimum SRAKE Based RAKE-DFE Receiver  

NASA Astrophysics Data System (ADS)

Single-carrier ultra-wideband (SC-UWB) is weak due to the problem of serious inter-symbol interference (ISI), which is generated in dense multipath with a long root-mean-square (RMS) delay spread. The selective RAKE (SRAKE) based RAKE-decision feedback equalizer (RAKE-DFE) receiver is usually employed to combat ISI in practical SC-UWB systems. Considering the system complexity, however, the number of RAKE fingers is usually small. In this case, conventional RAKE-DFE receivers can hardly collect enough energy to achieve a good performance. In this paper, the optimum SRAKE based RAKE-DFE receiver was proposed as a solution. Theoretical analysis and simulations are presented. Results and conclusions show that the proposed SRAKE scheme is optimum to collect energy of multipath. Moreover, the proposed RAKE-DFE receiver outperforms conventional RAKE-DFE receiver by about 1dB, but the complexity for them both is almost the same.

Xiao, Zhenyu; Su, Li; Jin, Depeng; Zeng, Lieguang

251

CPW-fed slot antenna with inset L-strip tuning stub for ultra-wideband  

Microsoft Academic Search

The coplanar waveguide fed slot antenna with inset L-stripe tuning stub is proposed for UWB applications. The antenna consists of two rectangular slots separated by center strip with CPW feed line. This antenna is design for match impedance with 50 ohm of characteristic impedance of transmission line by using inset L-stripe tuning stub for wideband matching. By adjusting dimension of

T. Archevapanich; P. Jearapraditkul; S. Puntheeranurak; N. Anantrasirichai; O. Sangaroon

2008-01-01

252

Experimental evaluation of a SAGE algorithm for ultra wideband channel sounding in an anechoic chamber  

Microsoft Academic Search

The paper presents the results of experiments in an anechoic chamber that assessed the reliability of a UWB channel sounding system based on a deterministic approach with a SAGE algorithm. The system could resolve and detect waves separated by 10° in the angle domain, which was near the resolution limit. In the delay domain, waves separated by 0.67 ns could

K. Haneda; J. I. Takada; T. Kobayashi

2004-01-01

253

Ultra-Wideband Time-Difference-of-Arrival Two-Point-Tracking System  

NASA Technical Reports Server (NTRS)

A UWB TDOA Two-Point-Tracking System has been conceived and developed at JSC. This system can provide sub-inch tracking capability of two points on one target. This capability can be applied to guide a docking process in a 2D space. Lab tests demonstrate the feasibility of this technology.

Ni, Jianjun David; Arndt, Dickey; Ngo, Phong; Phan, Chau; Dekome, Kent; Dusl, John

2009-01-01

254

An Improved 2-element Independently Center-Fed Dipole Array for Ultra-Wideband  

Microsoft Academic Search

This paper analyzed the efficiency of independently center-fed dipole array (ICDA) antenna. The best design was achieved with an array composed of two diamond antennas. It was demonstrated that the ICDA is capable of combining the bandwidths of both elements while maintaining linear phase throughout a broader bandwidth than the UWB requirements. Such characteristics make this antenna very appealing for

Nan Ni; H. Grebel

2006-01-01

255

Ultra-wideband coaxial hybrid coupler for load resilient ion cyclotron range of frequency heating at fusion plasmas  

SciTech Connect

We designed a high power and ultra-wideband two-section 3 dB coaxial hybrid coupler for load resilient ion cyclotron range of frequency heating by configuring asymmetric impedance matching using a three-dimensional simulation code, hfss. By adjusting the characteristic impedances of main and coupled lines of the hybrid coupler, we realized that the bandwidth of the proposed circuit is not only wider than that of a conventional three-section coupler, but also that the bandwidth is almost twice as wide compared to the conventional two-section hybrid coupler while maintaining the identical overall size.

Kim, H. J.; Bae, Y. S.; Yang, H. L.; Kwak, J.-G. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Wang, S. J. [Korea Atomic Energy Research Institute, Daejeon 305-333 (Korea, Republic of); Kim, B. K.; Choi, J. J. [Department of Electronics Convergence Engineering, Kwangwoon University, Seoul 139-701 (Korea, Republic of)

2012-06-25

256

Time-Frequency Transform Techniques Applied to Ultra-wideband Ground-Penetrating Radar  

NASA Astrophysics Data System (ADS)

Background Recently, Dauvignac et al [1] utilized a ground penetrating radar unit consisting of an exponentially tapered slot antenna (ETSA) of the Vivaldi type, connected to an Agilent vector network analyzer to obtain a densely-sampled profile in the anti-blast tunnel of LSBB (Low-Noise inter-Disciplinary Underground Science & Technology Laboratory) located in Rustrel, France. The frequency data, from 150 MHz to 2 GHz, was inverse Fourier-transformed to obtain the time dependent data. Simultaneously, the same profile was obtained using a RAMAC 500 MHz ground-penetrating radar unit. Initial comparison of both data sets was done in the time-domain. Data obtained from the ETSA will be inverted using a constrained least squares algorithm, in order that the depth-dependent permittivity can be inferred. As a quality control, the RAMAC data will also be inverted. The resulting permittivity profiles obtained in both inversions will be used to image water content over a depth of several meters. Proposed Research It is well-known, qualitatively in the ground penetrating radar literature that high frequencies appear at early times, but generally are attenuated at later times, essentially due to the skin effect. However, a signal-processing verification of this well-known result is needed. We propose to use the Stockwell or S transform [2] to determine the temporal location of frequencies in both of the foregoing datasets. The S transform, a short-time Fourier transform with a frequency-dependent window, will be described and applied to synthetic data. Then the application of the S transform to the RAMAC and ETSA data will be presented, after each data set has undergone the same pre-processing. The S transform is completely linear and preserves the phase of the data, which allows for easy interpretation of the operations of filtering, due to the linear inverse of the forward S transform. Thus the S transform is ideal for comparing the temporal distribution of frequency in these two datasets. BIBLIOGRAPHY [1] DAUVIGNAC J.-Y., N. FORTINO, G. SENECHAL, A. CRESP, M. YEDLIN, S. GAFFET, D. ROUSSET, and C. PICHOT, "Ultra-Wideband GPR Imaging of the Vaucluse Karst Aquifer", American Geophysical Union, Fall Meeting 2008, Abstract #NS51A-08. [2] STOCKWELL R. G., L. MANSINHA, R. P. LOWE, "Localization of the complex spectrum: the S transform", IEEE Transactions on Signal Processing, vol.44, n°4, pp 998-1001, April 1996.

Yedlin, M.; Cresp, A.; Dauviganc, J. Y.; Gaffet, S.; Sénéchal, G.; Fortino, N.; Pichot, C.; Aliferis, I.

2009-04-01

257

Joint semi-blind channel and timing estimation for generalized UWB transmitted reference systems  

Microsoft Academic Search

Synchronization is one of the most critical issues in ultra-wideband communications due to the short duration of the pulses. In this work, a semi-blind synchronization scheme based on maximum-likelihood techniques to recover both symbol and frame timing is developed. The proposed algorithm performs joint timing and channel estimation and is thus robust against moderate timing errors. The probability of acquisition

Stefan Franz; Cecilia Carbonelli; Urbashi Mitra

2007-01-01

258

Novel method to measure the refractive index and the absorption coefficient of organic nonlinear crystals in the ultra wideband THz region  

Microsoft Academic Search

A method for simultaneously measuring the refractive index and absorption coefficient of nonlinear optical crystals in the ultra-wideband terahertz (THz) region was developed. This method is based on the analysis of a collinear difference frequency generation (DFG) process using a tunable, dual-wavelength, optical parametric oscillator. The refractive index and the absorption coefficient in the organic nonlinear crystal DAS were experimentally

S. Ohno; K. Miyamoto; H. Minamide; H. Ito

2009-01-01

259

Full-Wave FDTD Analysis of UWB Pulses on Printed Coupled Lines  

Microsoft Academic Search

We have performed a comprehensive 3D FDTD transient analysis of EM pulses propagating on coupled printed lines with multilayer dielectric substrates and in complex 3D structures. The simulation results have revealed a wealth of new physical features, which are, to our best knowledge, seen for the first time. A comparative analysis of pulse propagation on coupled lines in a homogeneous

Shahid Ahmed; Alexander Schuchinsky

2006-01-01

260

Design of a Tunable All-Digital UWB Pulse Generator CMOS Chip for Wireless Endoscope.  

PubMed

A novel tunable all-digital, ultrawideband pulse generator (PG) has been implemented in a standard 0.18-¿ m complementary metal-oxide semiconductor (CMOS) process for implantable medical applications. The chip shows that an ultra-low dynamic energy consumption of 27 pJ per pulse without static current flow at a 200-MHz pulse repetition frequency (PRF) with a 1.8-V power supply and low area of 90 × 50 ¿m(2). The PG generates tunable pulsewidth, amplitude, and transmit (Tx) power by using simple circuitry, through precise timing control of the H-bridge output stage. The all-digital architecture allows easy integration into a standard CMOS process, thus making it the most suitable candidate for in-vivo biotelemetry applications. PMID:23853319

Chul Kim; Nooshabadi, S

2010-04-01

261

Covert situational awareness with handheld ultrawideband short-pulse radar  

NASA Astrophysics Data System (ADS)

Law enforcement and emergency services all face the difficult task of determining the locations of people within a building. A handheld radar able to detect motion through walls and other obstructions has been developed to fill this need. This paper describes the attributes and difficulties of the radar design and includes test results of the radar's performance. This discussion begins by summarizing key user requirements and the electromagnetic losses of typical building materials. Ultra-wideband (UWB) short pulse radars are well suited for a handheld sensor primarily because of their inherit time isolation in high clutter environments and their capability to achieve high resolution at low spectral center frequencies. There are also constraints that complicate the system design. Using a technique referred to as time-modulation allows the radars to reject range ambiguities and enhances electromagnetic compatibility with similar radars and ambient systems. An outline of the specifications of the radar developed and a process diagram on how it generates a motion map showing range and direction of the people moving within structures is included. Images are then presented to illustrate its performance. The images include adults, child, and a dog. The test results also include data showing the radar's performance through a variety of building materials.

Barnes, Mark A.; Nag, Soumya; Payment, Tim

2001-08-01

262

Comprehensive model-based error analysis of multiple concurrent, time-interleaved, and hybrid ultra-wideband analogue-to-digital conversion  

Microsoft Academic Search

In this paper, a comprehensive parametric error model of ultra-wideband analogue- to-digital conversion (ADC) is developed, which can likewise be applied for single ultra-fast ADC, multiple concurrent ADC (MC-ADC), time-interleaved ADC (TI- ADC) and hybrid ADC (H-ADC) as a combination of TI- and MC-ADC. The error model comprises quantisation, overo w saturation, DC-oset, gain error, time de- lay, and time

Heiko Kopmann

2004-01-01

263

A 60 GHz MMIC pHEMT image reject mixer with integrated ultra wideband IF hybrid and 30 dB of image rejection ratio  

Microsoft Academic Search

A 60 GHz image reject mixer (IRM) with an integrated ultra wideband IF hybrid has been designed, fabricated and characterized in a commercial pHEMT MMIC process. A measured conversion loss (Lc) of 10.2 to 11.4 dB over the frequency range 55 to 65 GHz is obtained with a state-of-the-art image rejection ratio (IRR) of 30 dB at the 60 GHz

Sten E. Gunnarsson; Dan Kuylenstierna; Herbert Zirath

2005-01-01

264

The use of optically triggered, high gain GaAs switches for UWB pulse generation  

SciTech Connect

A high peak power impulse pulser that is controlled with high gain, optically triggered GaAs Photoconductive Semiconductor Switches (PCSS) has been constructed and tested. The system has a short 50 {Omega} line that is charged to 100 kV and discharged through the switch when the switch is triggered with as little as 90 nJ of laser energy. The laser that is used is a small laser diode array whose output is delivered through a fiber to the switch. The current in the system ranges from 1 kA (with one laser) to 1.3 kA (with two) and the pulse widths are 1.9 and 1.4 ns, respectively. The peak power and the energy delivered to the load are 50 MW to 84 MW and 95 NJ to 120 mJ for one or two lasers. The small trigger energy and switch jitter are due to a high gain switching mechanism in GaAs. This experiment also shows a relationship between the rise time of the voltage across the switch and the required trigger energy and switch jitter.

Loubriel, G.M.; Zutavern, F.J.; O`Malley, M.W.; Gallegos, R.R.; Helgeson, W.D.

1994-04-01

265

Development and Implementation of Ultra-Wideband See-Through-Wall Imaging System Based on Sampling Oscilloscope  

Microsoft Academic Search

A low-cost experimental UWB synthetic aperture radar has been developed for high-resolution see-through-drywall imaging application. The developed SAR-based system is comprised of an UWB Vivaldi array, off-the-shelf components, and RF instruments. System integration including hardware and software aspects is in detailed discussion. The running system focuses on 8-12 GHz operation, but the very flexible system architecture allows it to be

Yunqiang Yang; Ceming Zhang; Aly E. Fathy

2008-01-01

266

Ultra-Wideband Indoor Double-Directional Channel Estimation Using Transformation between Frequency and Time Domain Signals  

NASA Astrophysics Data System (ADS)

This paper proposes an ultra-wideband double-directional spatio-temporal channel sounding technique using transformation between frequency- and time-domain (FD and TD) signals. Virtual antenna arrays, composed of omnidirectional antennas and scanners, are used for transmission and reception in the FD. After Fourier transforming the received FD signals to TD ones, time of arrival (TOA) is estimated using a peak search over the TD signals, and then angle of arrivals (AOA) and angle of departure (AOD) are estimated using a weighted angle histogram with a multiple signal classification (MUSIC) algorithm applied to the FD signals, inverse-Fourier transformed from the TD signals divided into subregions. Indoor channel sounding results validated that an appropriate weighting reduced a spurious level in the angle histogram by a factor of 0.1 to 0.2 in comparison with that of non-weighting. The proposed technique successfully resolved dominant multipath components, including a direct path, a single reflection, and a single diffraction, in line-of-sight (LOS) and non-LOS environments. Joint TOA and AOA/AOD spectra were also derived from the sounding signals. The spectra illustrated the dominant multipath components (agreed with the prediction by ray tracing) as clusters.

Iwakiri, Naohiko; Kobayashi, Takehiko

267

A novel through-wall respiration detection algorithm using UWB radar.  

PubMed

Through-wall respiration detection using Ultra-wideband (UWB) impulse radar can be applied to the post-disaster rescue, e.g., searching living persons trapped in ruined buildings after an earthquake. Since strong interference signals always exist in the real-life scenarios, such as static clutter, noise, etc., while the respiratory signal is very weak, the signal to noise and clutter ratio (SNCR) is quite low. Therefore, through-wall respiration detection using UWB impulse radar under low SNCR is a challenging work in the research field of searching survivors after disaster. In this paper, an improved UWB respiratory signal model is built up based on an even power of cosine function for the first time. This model is used to reveal the harmonic structure of respiratory signal, based on which a novel high-performance respiration detection algorithm is proposed. This novel algorithm is assessed by experimental verification and simulation and shows about a 1.5dB improvement of SNR and SNCR. PMID:24109862

Li, Xin; Qiao, Dengyu; Li, Ye; Dai, Huhe

2013-01-01

268

Design of a miniaturized ultra wideband bandpass filter based on a hybrid lumped capacitors - distributed transmission lines topology  

Microsoft Academic Search

In this paper, a miniaturized UWB bandpass filter using a hybrid lumped capacitors-distributed transmission lines topology is designed. The filter design rules are carried out and a filter is optimized for a 3 dB fractional bandwidth of 127 % with criteria of compacity, matching and selectivity. A sensitivity study versus critical parameters is also given. The filter length is reduced

Darine Kaddour; Jean-Daniel Arnould; Philippe Ferrari

2006-01-01

269

CMOS dual-band low-noise amplifier for world-wide WiMedia Ultra-Wideband wireless personal area network system  

Microsoft Academic Search

This paper presents a dual-band low-noise amplifier (DB-LNA) with switching band groups for WiMedia Ultra-Wideband. The LNA is designed and implemented in TSMC 0.18 ?m RF CMOS technology. Measurement results show that the DB-LNA gives 6.1 dB and 9.8 dB power gain, and that input and output matching are lower than -9.3dB\\/-9.4dB (Group-1\\/Group-6) and -9.2dB\\/-11.7dB (Group-1\\/Group-6). A minimum noise figure

Zhe-Yang Huang; Chung-Chih Hung

2010-01-01

270

SEMICONDUCTOR INTEGRATED CIRCUITS: A 3-5 GHz CMOS UWB power amplifier with ±8 ps group delay ripple  

NASA Astrophysics Data System (ADS)

A differential power amplifier (PA), designed using the linear-phase filter model, for a BPSK modulated ultra-wideband (UWB) system operating in the 3-5 GHz frequency range is presented. The proposed PA was fabricated using 0.18 ?m SMIC CMOS technology. To achieve sufficient linearity and efficiency, this PA operates in the class-AB region, delivering an output power of 8.5 dBm at an input-1 dB compression point of -0.5 dBm. It consumes 28.8 mW, realizing a flat gain of 9.11 ± 0.39 dB and a very low group delay ripple of ±8 ps across the whole band of operation.

Tianzuo, Xi; Lu, Huang; Zhong, Zheng; Lisong, Feng

2010-04-01

271

An ultra-wideband tunable multi-wavelength Brillouin fibre laser based on a semiconductor optical amplifier and dispersion compensating fibre in a linear cavity configuration  

SciTech Connect

A multi-wavelength Brillouin fibre laser (MBFL) with an ultra-wideband tuning range from 1420 nm to 1620 nm is demonstrated. The MBFL uses an ultra-wideband semiconductor optical amplifier (SOA) and a dispersion compensating fibre (DCF) as the linear gain medium and nonlinear gain medium, respectively. The proposed MBFL has a wide tuning range covering the short (S-), conventional (C-) and long (L-) bands with a wavelength spacing of 0.08 nm, making it highly suitable for DWDM system applications. The output power of the observed Brillouin Stokes ranges approximately from -5.94 dBm to -0.41 dBm for the S-band, from -4.34 dBm to 0.02 dBm for the C-band and from -2.19 dBm to 0.39 dBm for the L-band. The spacing between each adjacent wavelengths of all the three bands is about 0.08 nm, which is approximately 10.7 GHz for the frequency domain. (lasers)

Zulkifli, M Z; Ahmad, H; Hassan, N A; Jemangin, M H; Harun, S W

2011-07-31

272

SA and SAR Analysis for Wearable UWB Body Area Applications  

NASA Astrophysics Data System (ADS)

With the rapid progress of electronic and information technology, an expectation for the realization of body area network (BAN) by means of ultra wide band (UWB) techniques has risen. Although the signal from a single UWB device is very low, the energy absorption may increase significantly when many UWB devices are simultaneously adorned to a human body. An analysis method is therefore required from the point of view of biological safety evaluation. In this study, two approaches, one is in the time domain and the other is in the frequency domain, are proposed for the specific energy absorption (SA) and the specific absorption rate (SAR) calculation. It is shown that the two approaches have the same accuracy but the time-domain approach is more straightforward in the numerical analysis. By using the time-domain approach, SA and SAR calculation results are given for multiple UWB pulse exposure to an anatomical human body model under the Federal Communications Commission (FCC) UWB limit.

Wang, Qiong; Wang, Jianqing

273

Comparative analysis of UWB deconvolution and feature-extraction algorithms for GPR landmine detection  

NASA Astrophysics Data System (ADS)

In this work we developed target recognition algorithms for landmine detection with ultra-wideband ground penetrating radar (UWB GPR). Due to non-stationarity of UWB signals their processing requires advanced techniques, namely regularized deconvolution, time-frequency or time-scale analysis. We use deconvolution to remove GPR and soil characteristics from the received signals. An efficient algorithm of deconvolution, based on a regularized Wiener inverse filter with wavelet noise level estimation, has been developed. Criteria of efficiency were stability of the signal after deconvolution, difference between the received signal and the convolved back signal, and computational speed. The novelty of the algorithm is noise level estimation with wavelet decomposition, which defines the noise level separately for any signal, independently of its statistics. The algorithm was compared with an iterative time-domain deconvolution algorithm based on regularization. For target recognition we apply singular value decomposition (SVD) to a time-frequency signal distribution. Here we compare the Wigner transform and continuous wavelet transform (CWT) for discriminant feature selection. The developed algorithms have been checked on the data acquired with a stepped-frequency GPR.

Savelyev, Timofei G.; Sato, Motoyuki

2004-09-01

274

A Novel Compact UWB Monopole Antenna with Bluetooth and Triple Notch Band  

NASA Astrophysics Data System (ADS)

A novel technique to add an extra Bluetooth band and triple notch bands simultaneously to a compact ultra-wideband (UWB) monopole antenna is presented. This scissors-shaped UWB antenna, covering 2.9 GHz-12.5 GHz, is fed by a special microstrip line. To create an extra Bluetooth band centered at 2.45 GHz, an arc-shaped stub is attached to the high concentrated current area right of the feed line and a rectangular slot is etched in the radiation patch. Besides, a notch band for WLAN (5.6 GHz-6.15 GHz) is also obtained. In addition, by connecting two asymmetric stubs to the feed line, two other notch bands in 3.28 GHz-3.8 GHz for WiMAX and 7.1 GHz-7.76 GHz for downlink of X-band satellite communication systems are achieved. The proposed antenna with compact size of 20 mm × 26 mm is fabricated and measured, showing stable antenna gain and good omni-directional radiation patterns in H-plane.

Li, Li; Zhou, Zhi-Li; Hong, Jing-Song

2013-01-01

275

Studies on an Iterative Frequency Domain Channel Estimation Technique for MIMO-UWB Communications  

NASA Astrophysics Data System (ADS)

MIMO (Multiple-Input Multiple-Output) technologies have attracted much interest for high-rate and high-capacity wireless communications. MIMO technologies under frequency-selective fading environments (wideband MIMO technologies) have also been studied. A wideband MIMO system is affected by ISI (Inter Symbol Interference) and CCI (Co-Channel Interference). Hence, we need a MIMO signal detection technique that simultaneously suppresses ISI and CCI. The OFDM system and SC-FDE (Single Carrier-Frequency Domain Equalization) techniques are often used for suppressing ISI. By employing these techniques with the ZF (Zero Forcing) or the MMSE (Minimum Mean Square Error) spatial filtering technique, we can cancel both ISI and CCI. To use ZF or MMSE, we need channel state information for calculating the receive weights. Although an LS (Least Square) channel estimation technique has been proposed for MIMO-OFDM systems, it needs a large estimation matrix at the receiver side to obtain sufficient estimation performance in heavy multipath environments. However, the use of a large matrix increases computational complexity and the circuit size. We use frequency domain channel estimation to solve these problems and propose an iterative method for achieving better estimation performance. In this paper, we assume the use of a MIMO-UWB system that employs a UWB-IR (Ultra-Wideband Impulse Radio) scheme with the FDE technique as the wideband wireless transmission scheme for heavy multipath environments, and we evaluate the iterative frequency domain channel estimation through computer simulations and computational complexity calculations.

Takanashi, Masaki; Ogawa, Yasutaka; Nishimura, Toshihiko; Ohgane, Takeo

276

Design of UWB monopole antenna with dual notched bands using one modified electromagnetic-bandgap structure.  

PubMed

A modified electromagnetic-bandgap (M-EBG) structure and its application to planar monopole ultra-wideband (UWB) antenna are presented. The proposed M-EBG which comprises two strip patch and an edge-located via can perform dual notched bands. By properly designing and placing strip patch near the feedline, the proposed M-EBG not only possesses a simple structure and compact size but also exhibits good band rejection. Moreover, it is easy to tune the dual notched bands by altering the dimensions of the M-EBG. A demonstration antenna with dual band-notched characteristics is designed and fabricated to validate the proposed method. The results show that the proposed antenna can satisfy the requirements of VSWR < 2 over UWB 3.1-10.6?GHz, except for the rejected bands of the world interoperability for microwave access (WiMAX) and the wireless local area network (WLAN) at 3.5?GHz and 5.5?GHz, respectively. PMID:24170984

Liu, Hao; Xu, Ziqiang

2013-01-01

277

UWB Double polarised phased array  

Microsoft Academic Search

A systematic approach for the design of an ultra wideband (4-18 GHz) radiating element in dual polarized planar phased-array application is presented. Two different radiating elements have been selected: the Vivaldi notch element, fed by strip-line, and the four arms Sinuous element, fed by ultra wide band double printed balun. Return loss, gain and patterns have been simulated and optimized

P. Baldonero; A. Manna; F. Trotta; A. Pantano; M. Bartocci

2009-01-01

278

The analysis of TWI data for human being's periodic motions  

Microsoft Academic Search

The ultra wideband (UWB) radar has greater advantage in estimate positions and shapes of the target in Through Wall Imaging (TWI). One significant characteristic of human beings is the periodic motion, such as respiration and movement of arms. In this paper, we apply the UWB pulse radar to detect the periodic motion in through-wall detection. We present methods based on

Zhaofa Zeng; Jiguang Sun; Jing Li; Fengshan Liu; Qi Lu; Xiong Chen

2011-01-01

279

Subnanosecond pulse generator for through-the-wall radar application  

Microsoft Academic Search

This paper presents a sub-nanosecond pulse generator intended for a transmitter of through-the-wall surveillance radar. The basis of the generator is a step recovery diode, which is used to sharpen the slow rise time edge of an input driving waveform. A unique pulse shaping technique is then applied to form an ultra-wideband Gaussian pulse. A simple transistor switching circuit was

Pavel Protiva; Jan Mrkvica; J. Machac

2009-01-01

280

A 2 pJ\\/bit pulsed ILO UWB transmitter at 60 GHz in 65-nm CMOS-SOI  

Microsoft Academic Search

The paper describes a 2 pJ\\/bit transmitter with 1.5 Gbps data rate with Pulsed Injected Local Oscillator (p-ILO) and 0 dBm peak output power that 0.16 mm2 active area in 65-nm CMOS-SOI. Input digital pulses modulate the oscillator at 60 GHz from On to Off state. The occupation bandwidth is 7 GHz for a 300 ps modulating pulses. This millimeter

Nicolas Deparis; A. Siligarisy; Pierre Vincent; Nathalie Rolland

2009-01-01

281

New method to determine the refractive index and the absorption coefficient of organic nonlinear crystals in the ultra-wideband THz region.  

PubMed

A method for simultaneously measuring the refractive index and absorption coefficient of nonlinear optical crystals in the ultra-wideband terahertz (THz) region is described. This method is based on the analysis of a collinear difference frequency generation (DFG) process using a tunable, dual-wavelength, optical parametric oscillator. The refractive index and the absorption coefficient in the organic nonlinear crystal DAST were experimentally determined in the frequency range 2.5-26.2 THz by measuring the THz-wave output using DFG. The resultant refractive index in the x-direction was approximately 2.3, while the absorption spectrum was in good agreement with FT-IR measurements. The output of the DAST-DFG THz-wave source was optimized to the phase-matching condition using the measured refractive index spectrum in THz region, which resulted in an improvement in the output power of up to a factor of nine. PMID:20721118

Ohno, Seigo; Miyamoto, Katsuhiko; Minamide, Hiroaki; Ito, Hiromasa

2010-08-01

282

A new communication system design of M-ary PPM UWB suitable to FCC signal spectrum  

NASA Astrophysics Data System (ADS)

UWB impulse radio signals have a very short duration, extremely wide bandwidth and share the same frequency spectrum with other existing systems. It was determined by the Federal Communications Commission (FCC) that UWB systems could cause interference with other systems, such as Global Positioning System (GPS) for example. Therefore, at present, the FCC has restricted the use of UWB systems to frequencies above 3.1 GHz. In this paper, we evaluated performance of UWB system using proposed pulses that are strictly limited in time to remove interference while, at the same time, contain their power distribution to a frequency band from 3.1 GHz to 10.6 GHz. In particular, we evaluated the BER Performance in relation to system parameters such as pulse duration, ?, the number of users, Nu, and the number of symbols, M. We found the optimal pulse duration ? through computer simulation using developed UWB pulses. It is shown that performance evaluation between the UWB communication system using these UWB pulses and the Gaussian monocycle pulse in M-ary PPM and BPSK schemes. These results can be contributed to construct M-ary PPM UWB communication system in terms of multiuser parameters and pulse duration.

Lee, Mike M.; Cho, Byung-Lok; Kim, Dae-Ik

2004-03-01

283

High power monocycle pulse generator for through-the-wall radar transmitter  

Microsoft Academic Search

This paper presents a sub-nanosecond pulse transmitter of through-the-wall surveillance radar. The basis of the generator is a step recovery diode and a unique pulse-forming circuit, which forms an ultra-wideband Gaussian pulse. High amplitude pulses are advantageous for obtaining a good radar range, especially when penetrating thick and lossy building walls. In order to increase the output power of the

Pavel Protiva; Jan Mrkvica; J. Machac

2009-01-01

284

A 128-channel 6 mW wireless neural recording IC with spike feature extraction and UWB transmitter.  

PubMed

This paper reports a 128-channel neural recording integrated circuit (IC) with on-the-fly spike feature extraction and wireless telemetry. The chip consists of eight 16-channel front-end recording blocks, spike detection and feature extraction digital signal processor (DSP), ultra wideband (UWB) transmitter, and on-chip bias generators. Each recording channel has amplifiers with programmable gain and bandwidth to accommodate different types of biological signals. An analog-to-digital converter (ADC) shared by 16 amplifiers through time-multiplexing results in a balanced trade-off between the power consumption and chip area. A nonlinear energy operator (NEO) based spike detector is implemented for identifying spikes, which are further processed by a digital frequency-shaping filter. The computationally efficient spike detection and feature extraction algorithms attribute to an auspicious DSP implementation on-chip. UWB telemetry is designed to wirelessly transfer raw data from 128 recording channels at a data rate of 90 Mbit/s. The chip is realized in 0.35 mum complementary metal-oxide-semiconductor (CMOS) process with an area of 8.8 x 7.2 mm(2) and consumes 6 mW by employing a sequential turn-on architecture that selectively powers off idle analog circuit blocks. The chip has been tested for electrical specifications and verified in an ex vivo biological environment. PMID:19435684

Chae, Moo Sung; Yang, Zhi; Yuce, Mehmet R; Hoang, Linh; Liu, Wentai

2009-08-01

285

A CPW-fed circular wide-slot UWB antenna with wide tunable and flexible reconfigurable dual notch bands.  

PubMed

A coplanar waveguide (CPW)-fed circular slot antenna with wide tunable dual band-notched function and frequency reconfigurable characteristic is designed, and its performance is verified experimentally for ultra-wideband (UWB) communication applications. The dual band-notched function is achieved by using a T-shaped stepped impedance resonator (T-SIR) inserted inside the circular ring radiation patch and by etching a parallel stub loaded resonator (PSLR) in the CPW transmission line, while the wide tunable bands can be implemented by adjusting the dimensions of the T-SIR and the PSLR. The notch band reconfigurable characteristic is realized by integrating three switches into the T-SIR and the PSLR. The numerical and experimental results show that the proposed antenna has a wide bandwidth ranging from 2.7 GHz to 12 GHz with voltage standing wave ratio (VSWR) less than 2, except for the two notch bands operating at 3.8-5.9 GHz and 7.7-9.2 GHz, respectively. In addition, the proposed antenna has been optimized to a compact size and can provide omnidirectional radiation patterns, which are suitable for UWB communication applications. PMID:24222733

Li, Yingsong; Li, Wenxing; Ye, Qiubo

2013-01-01

286

A Low-Cost and Energy-Efficient Multiprocessor System-on-Chip for UWB MAC Layer  

NASA Astrophysics Data System (ADS)

Ultra-wideband (UWB) technology has attracted much attention recently due to its high data rate and low emission power. Its media access control (MAC) protocol, WiMedia MAC, promises a lot of facilities for high-speed and high-quality wireless communication. However, these benefits in turn involve a large amount of computational load, which challenges the traditional uniprocessor architecture based implementation method to provide the required performance. However, the constrained cost and power budget, on the other hand, makes using commercial multiprocessor solutions unrealistic. In this paper, a low-cost and energy-efficient multiprocessor system-on-chip (MPSoC), which tackles at once the aspects of system design, software migration and hardware architecture, is presented for the implementation of UWB MAC layer. Experimental results show that the proposed MPSoC, based on four simple RISC processors and shared-memory infrastructure, achieves up to 45% performance improvement and 65% power saving, but takes 15% less area than the uniprocessor implementation.

Xiao, Hao; Isshiki, Tsuyoshi; Khan, Arif Ullah; Li, Dongju; Kunieda, Hiroaki; Nakase, Yuko; Kimura, Sadahiro

287

TOA association for handheld UWB radar  

Microsoft Academic Search

Handheld ultra-wideband radars can be used with advantage during rescue, surveillance or security operations by reason that they enable to track targets moving behind walls. The radar signal processing for that purpose represents a complex process with several processing phases. In this paper, the attention is devoted to the estimation of the correct input data for the localization phase. This

Jana Rovnakova; Dusan Kocur

2010-01-01

288

A 70–280 MHz frequency and Q tunable 53 dB SFDR GmC filter for ultra-wideband  

Microsoft Academic Search

A 70-280 MHz 5th-order Chebyshev Gm-C low-pass filter was implemented in 0.13?m CMOS process to support both WiMedia UWB and lower rate IR-UWB applications. The filter response is accurately maintained over 4× frequency range by using unit Gm cell arrays and independent Q tuning circuit. To improve linearity of Gm-C filter in low supply voltage, a modified LC ladder topology

Weinan Li; Yumei Huang; Zhiliang Hong

2010-01-01

289

A novel time-domain UWB antenna  

Microsoft Academic Search

A planar monopole UWB antenna with good time-domain performance is presented, calculation and analysis are made through time-domain pattern descriptors. The profile of antenna is simple and easy to be implemented. The proposed antenna is simulated by CST Microwave Studio, some factors which can affect the time-domain performance such as pulse fidelity are studied and taken into account in antenna

Yong Li; Zeming Xie; Qingxin Chu

2008-01-01

290

In-line polarization-dependent microfiber interferometers and their applications in UWB signal generation.  

PubMed

A novel in-line polarization-dependent microfiber interferometer (PD-MFI) is proposed and experimentally demonstrated, which is tapered from a commercial polarization-maintaining fiber. Different from conventional MFIs, the transmission spectra of such MFIs are highly polarization-dependent, due to the mode-sensitive birefringence. The experimental results agree well with the theoretical predictions. Moreover, exploiting the polarization-dependent property of PD-MFIs, we demonstrate a simple and flexible scheme of generating polarity-switchable ultra-wideband pulses in the optical domain. Doublet pulses with a central frequency of 6.28 GHz and a 10-dB bandwidth of 7.86 GHz are obtained. Hence, with the advantages of being fiberized, simple fabrication and robustness, these PD-MFIs can be attractive elements in optical signal processing, optical sensing, optical fiber communication, and microwave photonics. PMID:23571913

Zhao, Ping; Zhang, Jihua; Yu, Yuan; Dong, Jianji; Shi, Lei; Liu, Yang; Zhang, Xinliang

2013-04-01

291

Pulse Shape Distortion and Ranging Accuracy in UWB-Based Body Area Networks for Full-Body Motion Capture and Gait Analysis  

Microsoft Academic Search

In this paper, we propose an ultra wide band (UWB)-based full-body motion capture system for gait analysis. The system is designed to reduce the implementation complexity and cost of current gait analysis setups, which require expensive locomotion laboratories and equipment. The solution exploits recent developments in wearable computing (i.e., electronic textiles) and relies on estimating the relative distance between body-worn

Marco Di Renzo; R. Michael Buehrer; Jaime Torres

2007-01-01

292

A Multiuser Detector Based on Artificial Bee Colony Algorithm for DS-UWB Systems  

PubMed Central

Artificial Bee Colony (ABC) algorithm is an optimization algorithm based on the intelligent behavior of honey bee swarm. The ABC algorithm was developed to solve optimizing numerical problems and revealed premising results in processing time and solution quality. In ABC, a colony of artificial bees search for rich artificial food sources; the optimizing numerical problems are converted to the problem of finding the best parameter which minimizes an objective function. Then, the artificial bees randomly discover a population of initial solutions and then iteratively improve them by employing the behavior: moving towards better solutions by means of a neighbor search mechanism while abandoning poor solutions. In this paper, an efficient multiuser detector based on a suboptimal code mapping multiuser detector and artificial bee colony algorithm (SCM-ABC-MUD) is proposed and implemented in direct-sequence ultra-wideband (DS-UWB) systems under the additive white Gaussian noise (AWGN) channel. The simulation results demonstrate that the BER and the near-far effect resistance performances of this proposed algorithm are quite close to those of the optimum multiuser detector (OMD) while its computational complexity is much lower than that of OMD. Furthermore, the BER performance of SCM-ABC-MUD is not sensitive to the number of active users and can obtain a large system capacity.

Liu, Xiaohui

2013-01-01

293

Hybrid ARQ Error-Controlling Scheme for Robust and Efficient Transmission of UWB Body Area Networks  

NASA Astrophysics Data System (ADS)

This paper presents hybrid type-II automatic repeat request (H-ARQ) for wireless wearable body area networks (BANs) based on ultra wideband (UWB) technology. The proposed model is based on three schemes, namely, high rate optimized rate compatible punctured convolutional codes (HRO-RCPC), Reed Solomon (RS) invertible codes and their concatenation. Forward error correction (FEC) coding is combined with simple cyclic redundancy check (CRC) error detection. The performance is investigated for two channels: CM3 (on-body to on-body) and CM4 (on-body to a gateway) scenarios of the IEEE802.15.6 BAN channel models for BANs. It is shown that the improvement in performance in terms of throughput and error protection robustness is very significant. Thus, the proposed H-ARQ schemes can be employed and optimized to suit medical and non-medical applications. In particular we propose the use of FEC coding for non-medical applications as those require less stringent quality of service (QoS), while the incremental redundancy and ARQ configuration is utilized only for medical applications. Thus, higher QoS is guaranteed for medical application of BANs while allowing coexistence with non-medical applications.

Suzuki, Haruka; Hernandez, Marco; Kohno, Ryuji

294

Design and development of ultra-wideband 3 dB hybrid coupler for Ion cyclotron resonance frequency heating in tokamak.  

PubMed

Design and development of a high power ultra-wideband, 3 dB tandem hybrid coupler is presented and its application in ICRF heating of the tokamak is discussed. In order to achieve the desired frequency band of 38-112 MHz and 200 kW power handling capability, the 3 dB hybrid coupler is developed using two 3-element 8.34 ± 0.2 dB coupled lines sections in tandem. In multi-element coupled lines, junctions are employed for the joining of coupled elements that produce the undesirable reactance called junction discontinuity effect. The effect becomes prominent in the high power multi-element coupled lines for high frequency (HF) and very high frequency(VHF) applications because of larger structural dimensions. Junction discontinuity effect significantly deteriorates coupling and output performance from the theoretical predictions. For the analysis of junction discontinuity effect and its compensation, a theoretical approach has been developed and generalized for n-element coupled lines section. The theory has been applied in the development of the 3 dB hybrid coupler. The fabricated hybrid coupler has been experimentally characterized using vector network analyzer and obtained results are found in good agreement with developed theory. PMID:24784637

Yadav, Rana Pratap; Kumar, Sunil; Kulkarni, S V

2014-04-01

295

UWB channel estimation using new generating TR transceivers  

DOEpatents

The present invention presents a simple and novel channel estimation scheme for UWB communication systems. As disclosed herein, the present invention maximizes the extraction of information by incorporating a new generation of transmitted-reference (Tr) transceivers that utilize a single reference pulse(s) or a preamble of reference pulses to provide improved channel estimation while offering higher Bit Error Rate (BER) performance and data rates without diluting the transmitter power.

Nekoogar, Faranak (San Ramon, CA) [San Ramon, CA; Dowla, Farid U. (Castro Valley, CA) [Castro Valley, CA; Spiridon, Alex (Palo Alto, CA) [Palo Alto, CA; Haugen, Peter C. (Livermore, CA) [Livermore, CA; Benzel, Dave M. (Livermore, CA) [Livermore, CA

2011-06-28

296

Subnanosecond Pulse Generator for Through-the-Wall Radar Application  

Microsoft Academic Search

Abstract—This paper,presents a sub-nanosecond,pulse gener- ator intended,for a transmitter,of through-the-wall surveillance radar. The basis of the generator is a step recovery diode, which is used,to sharpen,the slow rise time edge,of an input driving waveform.,A unique,pulse shaping,technique,is then,applied to form,an ultra-wideband,Gaussian,pulse. A simple transistor switching circuit was used to drive this Gaussian pulser, which transforms,a TTL trigger signal to a driving,pulse

Pavel Protiv; Jan Mrkvica; Jan Machá

297

SEMICONDUCTOR INTEGRATED CIRCUITS: A low jitter, low spur multiphase phase-locked loop for an IR-UWB receiver  

NASA Astrophysics Data System (ADS)

A low jitter, low spur multiphase phase-locked loop (PLL) for an impulse radio ultra-wideband (IR-UWB) receiver is presented. The PLL is based on a ring oscillator in order to simultaneously meet the jitter requirement, low power consumption and multiphase clock output. In this design, a noise and matching improved voltage-controlled oscillator (VCO) is devised to enhance the timing accuracy and phase noise performance of multiphase clocks. By good matching achieved in the charge pump and careful choice of the loop filter bandwidth, the reference spur is suppressed. A phase noise of -118.42 dBc/Hz at a frequency offset of 1 MHz, RMS jitter of 1.53 ps and reference spur of -66.81 dBc are achieved at a carrier frequency of 264 MHz in measurement. The chip was manufactured in 0.13 ?m CMOS technology and consumes 4.23 mW from a 1.2 V supply while occupying 0.14 mm2 area.

Ke, Shao; Hu, Chen; Yaohua, Pan; Zhiliang, Hong

2010-08-01

298

A novel UWB time-domain antenna based on GA  

Microsoft Academic Search

This paper applies the genetic algorithm, using MECG as the object function, to optimize the time-domain performance of antenna and get a novel UWB time-domain antenna. The MECG of the proposed antenna is 0.45 which suggests a good time-domain performance including pulse radiation and pulse fidelity. The result of simulation indicates that the working broadband of the proposed antenna is

Xie Ze-ming; Ding Huan-huan

2010-01-01

299

Comparison of the relative merits for target recognition by ultrawideband radar based on emitted impulse or step-frequency wave  

Microsoft Academic Search

The feasibility of ultra-wideband (UWB) radar systems for extracting signature information useful for target recognition purposes has been demonstrated previously. An UWB radar system emits either an extremely short pulse, impulse, or a frequency modulated signal (e.g., sweep or step-frequency). The frequency content of the emitted signals is designed to match the size and kind of typical targets and environments.

Hans C. Strifors; Anders Friedmann; Steffan Abrahamson; Guillermo C. Gaunaurd

2000-01-01

300

Feasibility Study and Design of a Wearable System-on-a-Chip Pulse Radar for Contactless Cardiopulmonary Monitoring  

PubMed Central

A new system-on-a-chip radar sensor for next-generation wearable wireless interface applied to the human health care and safeguard is presented. The system overview is provided and the feasibility study of the radar sensor is presented. In detail, the overall system consists of a radar sensor for detecting the heart and breath rates and a low-power IEEE 802.15.4 ZigBee radio interface, which provides a wireless data link with remote data acquisition and control units. In particular, the pulse radar exploits 3.1–10.6 GHz ultra-wideband signals which allow a significant reduction of the transceiver complexity and then of its power consumption. The operating principle of the radar for the cardiopulmonary monitoring is highlighted and the results of the system analysis are reported. Moreover, the results obtained from the building-blocks design, the channel measurement, and the ultra-wideband antenna realization are reported.

Zito, Domenico; Pepe, Domenico; Neri, Bruno; Zito, Fabio; De Rossi, Danilo; Lanata, Antonio

2008-01-01

301

Feasibility Study and Design of a Wearable System-on-a-Chip Pulse Radar for Contactless Cardiopulmonary Monitoring.  

PubMed

A new system-on-a-chip radar sensor for next-generation wearable wireless interface applied to the human health care and safeguard is presented. The system overview is provided and the feasibility study of the radar sensor is presented. In detail, the overall system consists of a radar sensor for detecting the heart and breath rates and a low-power IEEE 802.15.4 ZigBee radio interface, which provides a wireless data link with remote data acquisition and control units. In particular, the pulse radar exploits 3.1-10.6 GHz ultra-wideband signals which allow a significant reduction of the transceiver complexity and then of its power consumption. The operating principle of the radar for the cardiopulmonary monitoring is highlighted and the results of the system analysis are reported. Moreover, the results obtained from the building-blocks design, the channel measurement, and the ultra-wideband antenna realization are reported. PMID:18389068

Zito, Domenico; Pepe, Domenico; Neri, Bruno; Zito, Fabio; De Rossi, Danilo; Lanatà, Antonio

2008-01-01

302

Progress in UWB generation with linear silicon switches  

NASA Astrophysics Data System (ADS)

The use of linear photoconductive switches rather than nonlinear switches for the generation of Ultra-Wide-Band (UWB) pulses provides advantages such as jitter-free operation, low losses, and a reduction of the electrical and mechanical stresses in the switch. These advantages lead to the operation of many switches in series and/or parallel, higher average powers and longer lifetimes. Energy Compression Research Corporation (ECR) has demonstrated an advanced UWB source based on light activated silicon switches (LASS). The UWB source consists of a single LASS device mounted on a low impedance (< 0.5 (Omega) ) microstrip transmission line and a high fidelity impedance transformer connected to a 50 (Omega) coaxial connection. The voltage was measured at low impedance and 50 (Omega) to verify the efficiency and fidelity of the impedance transformer. After a transformation of 110:1 in impedance, the measurement at the end of the transformer verified that pulse rise-time was less than 100 ps and the overall efficiency was 50%. The system was tested up to 10 kV into 50 (Omega) before connector breakdown limited further increase. Larger powers can be radiated if the transformer is directly connected to the antenna.

Cardwell, Kendall W.; Giorgi, David M.; McIntyre, Iain A.; Solone, Paul J.; Stuurman, K.; Zucker, Oved S.

1993-06-01

303

Ultra low consumption UWB pulsed-ILO RF front-end transmitter at 60 GHz in 65-nm CMOS-SOI  

Microsoft Academic Search

A super high order sub-harmonic pulsed-ILO at 60 GHz in 65-nm CMOS-SOI has been fully designed and tested. It occupies 0.16 mm2 active area in 65-nm CMOS-SOI. Input digital locking signal modulates the oscillator at 60 GHz from ON to OFF state using a current source. Thus, the millimeter wave oscillation does not start from the thermal noise but from

Nicolas Deparis; Alexandre Siligaris; Pierre Vincent; Nathalie Rolland

2009-01-01

304

Employing cooperative diversity for performance enhancement in UWB communication systems  

Microsoft Academic Search

Due to limitation on transmitted power level, any UWB system faces major design challenges in achieving wide coverage while assuring an adequate system performance. In this paper, an employment of cooperative communications in UWB is proposed to enhance the performance and the coverage of UWB by exploiting the broadcasting nature of wireless channels and the cooperation among UWB devices. Symbol-error-rate

W. Pam Siriwongpairat; Weifeng Su; Zhu Han; K. J. Ray Liu

2006-01-01

305

Textile UWB Antennas for Wireless Body Area Networks  

Microsoft Academic Search

A new ultrawideband (UWB) textile antenna designed for UWB wireless body area network (WBAN) applications is presented. Unlike previous textile antennas, these antennas offer a direct integration into clothing due to a very small thickness (0.5 mm) and flexibility. We have realized two different designs of textile antennas: coplanar waveguide fed printed UWB disc monopole and UWB annular slot antenna.

Maciej Klemm; Gerhard Troester

2006-01-01

306

Time Domain Behaviors of Artimi's UWB Antenna  

Microsoft Academic Search

In this paper, a time domain study of Artimi's UWB antenna is presented. Firstly, the antenna's frequency domain behavior is illustrated. Thereafter, a detailed time domain investigation of the antenna is highlighted. It has been shown that Artimi's UWB antenna generally exhibits a good performance in both frequency and time domain. Wireless communications have been advancing with an astonishing rate

L. Guo; J. Liang; X. Chen; C. G. Parini

2006-01-01

307

Enhancing homeland security with advanced UWB sensors  

Microsoft Academic Search

This article discusses recent research into short-range UWB radars that have the potential to create more robust perimeter security sensor systems for exterior installations. It also briefly discusses existing UWB sensors to show how they establish a technical precedent for today's research.

P. Withington; H. Fluhler; Soumya Nag

2003-01-01

308

Ternary complementary sets for multiple channel DS-UWB with reduced peak to average power ratio  

Microsoft Academic Search

We study a multiple channel direct sequence ultrawideband (DS-UWB) system which transmits the same information bit over a set of parallel channels corresponding to a set of orthogonal pulses. It is known that by employing a mutually orthogonal (MO) ternary complementary set of spreading sequences, one can efficiently suppress both multipath and multiuser interference. Similar to a multicarrier DS-CDMA system,

Di Wu; P. Spasojevic; I. Seskar

2004-01-01

309

Multiband Media Access Control in Impulse-Based UWB Ad Hoc Networks  

Microsoft Academic Search

We propose a MAC protocol for use in multihop wireless networks that deploy an underlying UWB (ultra wide band)-based physical layer. We consider a multiband approach to better utilize the available spectrum, where each transmitter sends longer pulses in one of many narrower frequency bands. The motivation comes from the observation that, in the absence of a sophisticated equalizer, the

Ioannis Broustis; Srikanth V. Krishnamurthy; Michalis Faloutsos; Mart Molle; Jeffrey R. Foerster

2007-01-01

310

Generation of Power-Efficient FCC-Compliant UWB Waveforms Using FBGs: Analysis and Experiment  

Microsoft Academic Search

In this paper, we design, analyze, and demonstrate experimentally U.S. Federal Communications Commission (FCC)- compliant power-efficient ultrawideband (UWB) waveforms generated by optical pulse shaping. The time-domain pulse shape is written in the frequency domain, and a single-mode fiber performs the frequency-to-time conversion. The waveform is inscribed in the frequency domain by the fiber Bragg grating (FBG). A significant challenge for

Mohammad Abtahi; Julien Magne; Mehrdad Mirshafiei; Leslie A. Rusch; Sophie Larochelle

2008-01-01

311

FDTD simulation of exposure of biological material to electromagnetic nanopulses  

Microsoft Academic Search

Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, are of considerable interest to the communications industry and are being explored for various applications in biotechnology and medicine. The propagation of a nanopulse through biological matter has been computed using the finite difference-time domain (FDTD) method. The approach required the reparametrization of existing Cole-Cole model-based descriptions of dielectric properties of

Neven Simicevic; Donald T. Haynie

2005-01-01

312

A DS-UWB Cognitive Radio System Based on Bridge Function Smart Codes  

NASA Astrophysics Data System (ADS)

This paper proposes a direct-sequence UWB Gaussian pulse of cognitive radio systems based on bridge function smart sequence matrix and the Gaussian pulse. As the system uses the spreading sequence code, that is the bridge function smart code sequence, the zero correlation zones (ZCZs) which the bridge function sequences' auto-correlation functions had, could reduce multipath fading of the pulse interference. The Modulated channel signal was sent into the IEEE 802.15.3a UWB channel. We analysis the ZCZs's inhibition to the interference multipath interference (MPI), as one of the main system sources interferences. The simulation in SIMULINK/MATLAB is described in detail. The result shows the system has better performance by comparison with that employing Walsh sequence square matrix, and it was verified by the formula in principle.

Xu, Yafei; Hong, Sheng; Zhao, Guodong; Zhang, Fengyuan; di, Jinshan; Zhang, Qishan

313

A miniaturized CPW-fed rocket shaped UWB antenna for wireless applications  

Microsoft Academic Search

A novel compact Ultra wideband antenna fed by CPW is presented. The antenna has a size of 23 mm x 27 mm. It provides band width ranging from 2.7 GHz to 10.6 GHz. The antenna can be easily integrated with radio frequency circuit for low cost. Details of antenna are presented with parametric study. The bandwidth is varied by varying

Akkala Subbarao; S. Raghavan; P. Purna Sekhara Rao

2011-01-01

314

Imaging method: A strong tool for moving target tracking by a multistatic UWB radar system  

Microsoft Academic Search

In this paper, imaging method for moving target tracking by a multistatic ultra-wideband radar system is described. The task of moving target tracking consists in estimation of a target trajectory based on processing of raw radar data obtained from all receiving channels of a radar system. Then, the imaging method applied for target tracking consists of such signal processing phases

D. Kocur; J. Gamec; M. Svecova; M. Gamcova; J. Rovnakova

2010-01-01

315

UWB Antennas Integration Effects for Wireless Communication Applications  

NASA Astrophysics Data System (ADS)

In this chapter, a return loss measurement campaign was achieved to study the effect of the close environment on antenna's behavior in wireless application scenarios. Five different planar ultra-wideband antennas were measured on different devices (keyboard, screen, Internet box, and two laptops). General similarities in the bandwidth and matching efficiency behaviors were noticed for the antennas when mounted on the same devices in the same positions. In a purpose of modeling, the results can be used to classify the antennas and describe general behaviors on common used devices in wireless applications.

Mellah, M.-A.; Roblin, C.; Sibille, A.

316

Wide-band supercontinuum generation for sub-micron-resolution OCT by using a laser-diode-seeded amplified pulse source  

NASA Astrophysics Data System (ADS)

We present an ultra-wideband supercontinuum source using a dispersion-shifted fiber and an amplified diode-laser pulse source. A gain-switched DFB laser operating at 1550-nm wavelength, which provides 30-ps pulses, was used for generating the seeding pulses. And serially cascaded low-cost EDFAs were employed to boost the peak power of the pulses to more than 1 kW. Single-mode supercontinuum spanning nearly the full near-IR band was obtained by passing the amplified pulses through a dispersion-shifted fiber. By investigating the characteristics of the generated supercontinuum pulses, the walk-off between the spectral components was found to limit the effective interaction length of the spectrum-broadening effects. In order to expand further the spectral range of the output, we have examined the time-gating ASE suppression scheme and use of a high-power EDFA. And the resulted outputs have reached wavelengths of 0.8 and 0.9 ?m, respectively at the short-wavelength edges. Only the blue-shifted part that can be obtained using a short-wavelength-pass filter can exhibit 3-dB bandwidth more than 500 nm in the vicinity of 1.2 ?m. The supercontinuum generation scheme provides a compact and reliable way to generate ultra-wideband flat spectrum that can be useful for high-resolution OCT.

Moon, Sucbei; Kim, Dug Young

2006-03-01

317

Compact size ultra wideband Hexagonal Fractal antenna  

Microsoft Academic Search

A compact size ultra wide-band coplanar waveguide (CPW) fed, fractal antenna is presented. A rectangular slot antenna is excited by a 50?-CPW with a fractal patch. The antenna was studied experimentally regarding impedance bandwidth, radiation patterns and gain. For the proposed antenna, the -10 dB return loss bandwidth could reach 7.45 GHz (2.85 GHz - 10.3 GHz). Details of the

A. A. Lotfi-Neyestanak; M. R. Azadi; A. Emami-Forooshani

2010-01-01

318

UWB-based Secure Ranging and Localization  

Microsoft Academic Search

In this paper, we propose and implement a novel ID- based secure ranging protocol. Our protocol is inspired by existing authenticated ranging and distance-bounding protocols, and is tailored to work on existing Ultra Wide Band (UWB) ranging platforms. Building on the imple- mentation of secure ranging, we further implement a se- cure localization protocol that enables the computation of a

Nils Ole Tippenhauer

319

Phase-Only Matched Filtering of Ultrawideband Arbitrary Microwave Waveforms via Optical Pulse Shaping  

Microsoft Academic Search

We demonstrate compression of ultrawideband (UWB) microwave arbitrary waveforms via phase-only matched filtering implemented in a programmable hyperfine resolution optical pulse shaper. We synthesize spread-time UWB electrical waveforms and utilize programmable microwave photonic phase filters to impose the opposite of a waveform's spectral phase on its spectrum. This enables us to compress an UWB microwave waveform to its corresponding bandwidth-limited

Ehsan Hamidi; Andrew M. Weiner

2008-01-01

320

Robust Target Discrimination with UWB GPR  

Microsoft Academic Search

In this work we show a possibility for discrimination of the low-metal antipersonnel landmines from non-metal minelike objects with UWB ground penetrating radar (GPR). The discrimination is based on frequency resonances of scattered signals, their evolution in time and energy. Our goal was to find such time-frequency features which are not only discriminant but also robust in a certain range

Timofei G. Savelyev; Takao Kobayashi; Xuan Feng; Motoyuki Sato

2007-01-01

321

UWB radar for ground vehicle self protect  

Microsoft Academic Search

The authors describe the concept of using an impulse ultrawide-band (UWB) radar system to detect, acquire, identify and track incoming armor-piercing rounds which threaten a ground vehicle. Data illustrating the ability of a prototype impulse radar to discriminate between different target shapes are presented. The sensitivity of the CFAR (constant-false-alarm-rate) receiver used with the system appears to be adequate, but

J. W. Toevs; D. R. Smith; D. P. Byrne; G. F. Ross

1992-01-01

322

Performance of ultra-wide bandwidth (UWB) pentagon shape microstrip slot antenna for wireless communications  

Microsoft Academic Search

A planar ultra-wideband microstrip slot antenna with pentagon slot and pentagon stub has been presented. Small size of the proposed antenna can find applications in mobile handheld units. The area that this antenna occupies on the 50 mm times 80 mm ground plane space is 25%. The proposed antenna has a bandwidth ranging from 2.65 GHz to 11.3 GHz, which

Sunil K. Rajgopal; Satish K. Sharma

2008-01-01

323

Enhanced feature detection and tracking algorithm for UWB-OFDM SAR navigation  

Microsoft Academic Search

There is a great need to develop non-GPS based methods for position and navigation in situations where GPS is not available. This paper presents an improved feature extraction and tracking algorithm for a novel navigation sensor, an Ultra-Wideband Orthogonal Frequency Division Multiplexed radar. The radar is onboard an aerial vehicle and collects data periodically in a side-looking stripmap Synthetic Aperture

Kyle Kauffman; John Raquet

2011-01-01

324

Image-based target detection with multispectral UWB OFDM radar  

NASA Astrophysics Data System (ADS)

This paper proposes an image-based automatic target detection algorithm to be used in clutter and sparse target environments. We intend to apply the algorithm to an ultra-wideband multispectral radar concept by means of employing multi-carrier waveforms based upon Orthogonal Frequency Division Multiplexing (OFDM) modulation. Individual sub-bands of an OFDM waveform can be processed separately to yield range and cross-range reconstruction of a target scene containing both targets and clutter. Target detection in resulting images will be performed and contrasted with the detection performance of a traditional fixed-waveform Synthetic Aperture Radar system. The target detection algorithm is implemented through the use of scalar and vector field operations performed on the images from the reconstructed target scene. We hypothesize that the use of vector operations and field analysis will allow for an adaptive approach to the detection of targets within clutter.

Bufler, Travis D.; Garmatyuk, Dmitriy S.

2012-05-01

325

Radio resource optimization in an UWB wireless access  

Microsoft Academic Search

The Ultra Wide Band (UWB) radio is a promising technology for wireless digital communications. In this paper we present the main principles for the radio resource sharing in UWB. We describe both the theoretical approach and the practical one and we address the procedures of a MAC protocol for the support of Dynamic Bandwidth service class and Reserved one. I.

F. Cuomo; A. Baiocchi; F. Capriotti; C. Martello

2002-01-01

326

A novel UWB planar patch antenna for wireless communications  

Microsoft Academic Search

A novel UWB symmetrical double-beveled planar patch antenna with notch cut fed by a microstrip line is proposed and studied. It is designed for UWB wireless communications. Many techniques have been applied to the designed antenna, which are the use of double bevels, feed gap, partial ground plane and notch cut. The designed antenna can operate over the bandwidth of

Abdallah A. Alshehri; A. R. Sebak

2008-01-01

327

A Cooperative Retransmission Scheme for IR-UWB networks  

Microsoft Academic Search

We design a cooperative retransmission scheme in the MAC layer which utilizes the UWB unique properties such as fine ranging and immunity to small scale fading in order to exploit the multiuser diversity in UWB networks. We analyze the optimal cooperation strategy to maximize the system throughput in proactive and reactive settings. We also perform simulations to show that the

Ghasem Naddafzadeh Shirazi; Peng-Yong Kong; Chen-Khong Tham

2008-01-01

328

Could we use UWB sensing for breast cancer detection?  

Microsoft Academic Search

In consideration of the current developments on UWB sensors for biomedical applications [1–5], this paper deals with the status of breast cancer detection in diagnostic imaging, as well as with the molecular and cellular biology of cancer initiation and progression achieved in the frame of an interdisciplinary research project. In this context the question will be addressed, how UWB imaging

I. Hilger; C. Geyer; G. Rimkus; M. Helbig; J. Sachs; U. Schwarz; M. A. Hein; W. A. Kaiser

2010-01-01

329

A framework for performance analysis of TH-UWB communications  

Microsoft Academic Search

Ultra wide band (UWB) has been proposed in recent years as a suitable transmission technique for various applications in the wireless context and is currently under consideration of standard bodies for e.g. wireless personal area networks. UWB is also inherently indicated for distributed ad-hoc wireless networks and, in particular, for sensor networks. Since operations in shared radio resource environments are

Marco Di Renzo; Fabio Graziosi; Fortunato Santucci

2005-01-01

330

Pulse sharpening and soliton generation with nonlinear transmission lines for producing RF bursts  

Microsoft Academic Search

Nonlinear transmission lines (NLTL) are being designed and built to extend the range of available Ultra- Wide Band (UWB) and High Power RF pulse generation technology, especially in the area of high repetition rate microwave burst generation (1). The NLTL approach to UWB and RF generation eliminates the need for the electron beam, vacuum system, and magnets required in conventional

Jason M. Sanders; Yung-Hsu Lin; Richard Ness; Andras Kuthi; Martin Gundersen

2010-01-01

331

A 2D simple attenuation model for EM waves in human tissues: Comparison with a FDTD 3D simulator for UWB medical radar  

Microsoft Academic Search

This paper describes a simple 2D model for the propagation of electro-magnetic (EM) pulses in human tissues. To assess the reliability of using this model for fast attenuation evaluation of UWB radar pulses in the body, the model is compared with a well known 3D FDTD numeric simulator using a simple multilayer geometry. Results from the 2D model were found

G. Varotto; E. M. Staderini

2008-01-01

332

47 CFR 15.503 - Definitions.  

Code of Federal Regulations, 2013 CFR

...COMMISSION GENERAL RADIO FREQUENCY DEVICES Ultra-Wideband...the UWB bandwidth is the frequency band bounded by the points...is designated fH and the lower boundary is designated fL . The frequency at which the highest...

2013-10-01

333

Vehicle-mounted UWB radar for improvised explosive device detection  

Microsoft Academic Search

In this paper, vehicle-mounted ultra-wide band (UWB) radar is studied for detection of roadside improvised explosive devices (IEDs). Simulations and measurements have been performed to study the radar system set-up, target scattering, and data processing. The challenges of UWB radar for target visibility within the ground clutter, locating with limited angular diversity, and discrimination of buried bomb shells have been

Obadiah Kegege; Casto Ibarra; Junfei Li; Heinrich Foltz

2007-01-01

334

Vehicle-mounted UWB radar for improvised explosive device detection  

NASA Astrophysics Data System (ADS)

In this paper, vehicle-mounted ultra-wide band (UWB) radar is studied for detection of roadside improvised explosive devices (IEDs). Simulations and measurements have been performed to study the radar system set-up, target scattering, and data processing. The challenges of UWB radar for target visibility within the ground clutter, locating with limited angular diversity, and discrimination of buried bomb shells have been encountered and explored. Possible solutions to overcome these challenges are investigated.

Kegege, Obadiah; Ibarra, Casto; Li, Junfei; Foltz, Heinrich

2007-05-01

335

Non-contact UWB Radar Technology to Assess Tremor  

Microsoft Academic Search

\\u000a This work quantifies and analyzes tremor using Ultra Wide Band (UWB) radio technology. The UWB technology provides a new technology\\u000a for non contact tremor assessment with extremely low radiation and penetration through walls. Tremor is the target symptom\\u000a in the treatment of many neurological disorders such as Parkinson’s disease (PD), midbrain tremor, essential tremor (ET) and\\u000a epilepsy. The common instrumental

G. Blumrosen; M. Uziel; B. Rubinsky; D. Porrat

336

Effect of aggregate narrowband interference on the UWB autocorrelation receiver  

Microsoft Academic Search

There has been an emerging interest in non-coherent ultrawideband (UWB) communications, mainly due to their low-complexity and low-power consumption. Due to the large transmission bandwidth, UWB systems need to coexist and contend with many narrowband communication systems. As a result, the presence of narrowband interference (NBI) severely degrades the system performance. In this paper, we consider transmitted reference signaling and

Alberto Rabbachin; T. Q. S. Quek; P. C. Pinto; I. Oppermann; M. Z. Win

2008-01-01

337

Position Estimation of Tranceivers in Communication Networks  

SciTech Connect

With the rapid development in wireless sensor networks, there is an important need for transceiver position estimation independent of Global Positioning Systems (GPS) [1,3]. While GPS might be useful for outdoor sensor nodes, it is not for indoor node localization. In this case, position estimation is possible through network range estimates from time-of-flight (TOF) measurements, a technique well suited to large bandwidth physical links, such as in ultra-wideband (UWB) communications. For example, in our UWB systems, with pulse duration less than 200 pico-seconds, range can easily be resolved to less than a foot. Assuming an encoded UWB or spread spectrum physical layer, we developed algorithms and simulation tools to test transceiver position localization. Simulations were designed to lend insight into system characteristics such as position error sensitivities to network geometry, to range estimation errors, and to number of sensor nodes.

Kent, C A; Dowla, F U

2003-10-13

338

Ambiguity Functions for Monostatic and Bistatic Radar Systems using UWB Throb Signal  

Microsoft Academic Search

Waveform design and ambiguity function are significant tools for the performance analysis of radar systems. We first describe the principle of waveform design for ultrawideband (UWB) impulse waveforms and present the signal model and the advantages of a UWB-throb signal. The ambiguity function of the UWB-throb signal for monostatic radar is derived in detail and analyzed by computer simulation to

Malek G. M. Hussain

2011-01-01

339

47 CFR 15.519 - Technical requirements for hand held UWB systems.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Technical requirements for hand held UWB systems. 15.519 Section...15.519 Technical requirements for hand held UWB systems. (a) UWB devices...under the provisions of this section must be hand held, i.e. , they are...

2013-10-01

340

Power-efficient impulse radio ultrawideband pulse generator based on the linear sum of modified doublet pulses.  

PubMed

We propose a new and power-efficient impulse radio ultawideband (IR-UWB) pulse design concept. The proposed concept is based on a linear sum of modified doublet pulses. The proposed concept is both simulated and experimentally demonstrated. The experimental demonstration employs a photonic scheme that generates the designed pulse using two main steps, mainly optical shaping and differential detection. The optical shaping is performed using a single electro-optic modulator biased in the nonlinear portion of its transfer function, and the differential detection is performed using a balanced photodetector. The generated IR-UWB pulse is fully Federal Communications Commission compliant, even in the highly power-restricted global positioning system band. The proposed optical scheme has potential to be integrated on a compact optical chip and thus suitable for reliable, low-cost, high-speed, short-range UWB wireless access, such as in-building networks. PMID:21686021

Abraha, S T; Okonkwo, C M; Tangdiongga, E; Koonen, A M J

2011-06-15

341

[Focusing properties of picosecond electric pulses in non-invasive cancer treatment].  

PubMed

In the light of optical theory, we advanc an ultra-wideband impulse radiating antenna (IRA) which is composed of an ellipsoidal reflector and a cone radiator. The high-intensity ultra-short electric pulses radiated by IRA can be transferred into the deep target in tissue non-invasively and be focused effectively. With the focused picosecond electric pulses, the organelles (mitochondria) transmembrane potential shall change to collapse under which the tumor cells will be targetly induced to apoptosis, so the method of non-invasive treatment of tumors would be achieved. Based on the time-domain electromagnetic field theory, the propagation characteristics of picosecond electric pulses were analyzed with and without the context of biological tissue, respectively. The results show that the impulse characteristics of input pulse were maintained and the picosecond electric pulses can keep high resolution in target areas. Meanwhile, because of the dispersive nature of medium, the pulse amplitude of the pulses will attenuate and the pulse width will be broadened. PMID:21089684

Long, Zaiquan; Yao, Chenguo; Li, Chengxiang; Mi, Yan; Sun, Caixin

2010-10-01

342

Robust Target Discrimination with UWB GPR  

NASA Astrophysics Data System (ADS)

In this work we show a possibility for discrimination of the low-metal antipersonnel landmines from non-metal minelike objects with UWB ground penetrating radar (GPR). The discrimination is based on frequency resonances of scattered signals, their evolution in time and energy. Our goal was to find such time-frequency features which are not only discriminant but also robust in a certain range of target depths and GPR antenna heights. For feature extraction, singular value decomposition (SVD) of the Wigner distribution was used. We acquired signals from landmine models and minelike objects for a number of antenna heights and target depths, extracted the features and analyzed their clustering along with separation between the clusters. The data was measured with a stepped-frequency GPR in the frequency range 0.3-6 GHz. For antenna calibration, we performed deconvolution of the GPR-soil impulse response, acquired from a buried metal plate. Its influence on the target features has been analyzed as well.

Savelyev, Timofei G.; Kobayashi, Takao; Feng, Xuan; Sato, Motoyuki

343

Estimating the Breast Surface Using UWB Microwave Monostatic Backscatter Measurements  

Microsoft Academic Search

This paper presents an algorithm for estimating the location of the breast surface from scattered ultrawideband (UWB) microwave signals recorded across an antenna array. Knowing the location of the breast surface can improve imaging performance if incorporated as a priori information into recently proposed microwave imaging algorithms. These techniques transmit low-power microwaves into the breast using an antenna array, which

David W. Winters; Jacob D. Shea; Ernest L. Madsen; Gary R. Frank; Barry D. Van Veen; Susan C. Hagness

2008-01-01

344

Optimal Cooperative Relaying Schemes in IR-UWB Networks  

Microsoft Academic Search

Cooperation between wireless nodes to retransmit data for the other users introduces multiuser diversity to a wireless network and increases the system throughput. In this paper, the optimal cooperative relaying strategies in the MAC layer are analyzed while considering the UWB unique properties such as fine ranging and immunity to small scale fading. Specifically, the optimal cooperation strategies in the

Ghasem Naddafzadeh-Shirazi; Peng-Yong Kong; Chen-Khong Tham

2010-01-01

345

Surface-mounted UWB handset antenna with small envelope volume  

Microsoft Academic Search

This work investigates the effects of component population on the performance of miniature handset antennas operating in the UWB bandgroups 3 and 6. Two antennas are evaluated, a small ceramic block PIFA and a miniature planar monopole, both of height 4 mm. The antennas are located on a standard mobile phone board and provide efficiencies greater than 50% over the

Max. J. Ammann; M. John; D. Kearney

2011-01-01

346

A multicode approach for high data rate UWB system design  

Microsoft Academic Search

This contribution provides a very high data rate UWB system design based on direct sequence spreading. In order to attain >500 Mbps for short range communication, two classical solutions are feasible: either use very short spreading sequences or very large bandwidth. These classical strategies increase intersymbol interference. In contrast, our approach consists in allocating multiple long codes to each user.

Mohamed Kamoun; Laurent Mazet; Marc de Courville; Pierre Duhamel

2009-01-01

347

Pulse  

MedlinePLUS

... resting for at least 10 minutes. Take the exercise heart rate while you are exercising. ... pulse rate can help determine if the patient's heart is pumping. ... rate gives information about your fitness level and health.

348

pulses  

Microsoft Academic Search

This paper reports on photoionisation loading based on ultrafast pulses of singly-ionised stron- tium ions in a linear Paul trap. We take advantage of an autoionising resonance of Sr neutral atoms to form Sr+ by two-photon absorption of femtosecond pulses at a wavelength of 431 nm. We compare this technique to electron-bombardment ionisation and observe several advantages of photoionisation. It

S. Removille; R. Dubessy; Q. Glorieux; S. Guibal; T. Coudreau; L. Guidoni; J.-P. Likforman

349

A multiband mac protocol for impulse-based UWB ad hoc networks  

Microsoft Academic Search

Ultra Wide Band (UWB) technology offers a promis- ing high capacity solution for wireless networks with short-range links. However, MAC and higher-layer ad hoc network protocols that exploit the UWB technology are yet to mature. In this paper, we propose a MAC protocol for use in multi-hop wireless networks that deploy an underlying UWB based physical layer. We adopt a

Ioannis Broustis; Srikanth Krishnamurthy; Michalis Faloutsos; Mart Molle; Jeffrey Foerster

2005-01-01

350

Analysis of iterative demapping and decoding for MBOK DS-UWB systems via EXIT chart  

Microsoft Academic Search

This paper presents an analysis of iterative demapping and decoding for coded M-ary bi-orthogonal keying direct sequence UWB (MBOK DS-UWB) systems via an extrinsic information transfer chart (EXIT chart). In MBOK DS-UWB systems, which have been considered a type of PHYs suitable for high-speed wireless personal area networks (WPANs) in IEEE802.15.3a, one of useful error correction techniques is iterative demapping

Kenichi Takizawa; Ryuji Kohno

2005-01-01

351

Reduced Complexity Demodulation and Equalization Scheme for Differential Impulse Radio UWB Systems with ISI  

Microsoft Academic Search

In this paper, we consider the demodulation and equalization problem of differential Impulse Radio (IR) Ultra-WideBand (UWB) Systems with Inter-Symbol-Interference (ISI). The differential IR UWB systems have been extensively discussed recently. The advantage of differential IR UWB systems include simple receiver frontend structure. One challenge in the demodulation and equalization of such systems with ISI is that the systems have

Xudong Ma

2008-01-01

352

Ultrawideband synthetic vision sensor for airborne wire detection  

NASA Astrophysics Data System (ADS)

A low cost, miniature ultra wideband (UWB) radar has demonstrated the ability to detect suspended wires and other small obstacles at distances exceeding several hundred feet using an average output power of less than 10 microwatts. Originally developed as a high precision UWB radar altimeter for the Navy's Program Executive Office for Unmanned Aerial Vehicles and Cruise Missiles, an improved sensitivity version was recently developed for the Naval Surface Warfare Center (NSWC Dahlgren Division) as part of the Marine Corps Warfighting Laboratory's Hummingbird program for rotary wing platforms. Utilizing a short pulse waveform of approximately 2.5 nanoseconds in duration, the receiver processor exploits the leading edge of the radar return pulse to achieve range resolutions of less than one foot. The resultant 400 MHz bandwidth spectrum produces both a broad frequency excitation for enhanced detection, as well as a low probability of intercept and detection (LPI/D) signature for covert applications. This paper describes the design and development of the ultra wideband sensor, as well as performance results achieved during field testing at NSWC's Dahlgren, VA facility. These results are compared with those achieved with a high resolution EHF radar and a laser-based detection system.

Fontana, Robert J.; Larrick, J. F.; Cade, Jeffrey E.; Rivers, Eugene P.

1998-07-01

353

Photoinjector-driven chirped-pulsed free electron maser  

NASA Astrophysics Data System (ADS)

An ultra-short pulse, millimeter-wave free electron maser experiment is currently underway at UC Davis and Lawrence Livermore National Laboratory. A 8.5 kG, 30 mm period helical wiggler is used to transversally accelerate a train of one hundred 5 MeV, 0.25 nC, 1 ps duration micro bunches synchronously energized by a 20 MW, X-band photocathode RF linac. The photocathode is irradiated by a burst-mode, UV laser system which produces up to 100 pulses at 207 nm, with an energy of 10 mJ/pulse, and a pulse duration of 200 fs, at a repetition rate of 2.142 GHz. This system includes a 400 fs jitter synchronously modelocked AlGaAs semiconductor laser oscillator which is amplified by an eight-pass Ti:Al2O3 chirped pulse laser amplifier. The output of this amplifier is subsequently frequency quadrupled into the UV. Because the electron micro bunches are shorter than the radiation wavelength, the system coherently synchrotron radiates and behaves essentially as a prebunched FEM. In addition, by operating in a waveguide structure at grazing, where the bunch axial velocity in the wiggler matches the group velocity of the electromagnetic waves, one obtains output radiation pulses which are extremely short, and have greatly enhanced peak power. The device operates in the TE(sub 12) mode of a cylindrical waveguide, and will produce up to 2 MW of coherent synchrotron radiation power at 140 GHz, in a 15 ps FWHM pulse. The -3 dB instantaneous interaction bandwidth extends from 125 GHz to 225 GHz. The output pulse is chirped over the full interaction bandwidth. One of the major potential applications of such a device is an ultra-wideband millimeter-wave radar.

Lesage, G. P.; Hartemann, F. V.; Feng, H. X. C.; Fochs, S. N.; Heritage, J. P.; Luhmann, N. C., Jr.; Perry, M. D.; Westenskow, G. A.

1995-03-01

354

UWB-Based Tracking of Autonomous Vehicles with Multiple Receivers  

NASA Astrophysics Data System (ADS)

In this paper, we consider real-time tracking of an Autonomous Guided Vehicle (AGV) in an indoor industrial scenario. An on-board odometer provides information about the dynamic state of the AGV, allowing to predict its pose (position and orientation). At the same time, an external Ultra Wide Band (UWB) wireless network provides the information necessary to compensate the error drift accumulated by the odometer. Two novel alternative solutions for real-time tracking are proposed: (i) a classical Time Differences of Arrivals (TDOA) approach with a single receiver; (ii) a "Twin-receiver" TDOA (TTDOA) approach, that requires the presence of two independent receivers on the AGV. The performance of the two proposed algorithms is evaluated in realistic conditions. The obtained results clearly show the tradeoff existing between the frequency of UWB measurements and their quality.

Busanelli, Stefano; Ferrari, Gianluigi

355

Research on positioning enhancement scheme of CAPS via UWB pseudolite  

NASA Astrophysics Data System (ADS)

The positioning precision of the transmitting Chinese Area Positioning System (CAPS) is reduced due to the non-ideal distribution of the satellite constellation. Positioning and navigation enhancement methods are able to improve the reliability and accuracy of the positioning system, especially for users in special regions and special applications. In this paper, a positioning enhanced scheme based on ultra-wide band (UWB) pseudolite is proposed for CAPS. It is demonstrated that the link budget of UWB pseudolite satisfies the FCC's emission mask requirements. The localization algorithm of the enhanced CAPS is presented. The simulations indicate that the positioning precision of the proposed enhanced scheme is improved greatly, and the feasibility of the enhanced scheme is thus proved.

Xiao, Zhu; Bai, Jing; Ma, GuanYi; Fan, JiangTao; Yi, KeChu

2012-04-01

356

Spatial correlation of UWB signals in a home environment  

Microsoft Academic Search

Measurements of the spatial dependence of UWB (2-8 GHz) channels were made for a residential propagation environment using a network analyzer. Measurements indicate spatial correlation lengths ranging from about 2 to 6 inches for both LOS and NLOS geometries. The angle-of-arrival distribution showed discernible frequency-dependent rays of scattered energy and a strong component of narrow angle scatter energy. The LOS

C. Prettie; D. Cheung; L. Rusch; M. Ho

2002-01-01

357

Transmitting multiple HD video streams over UWB links  

Microsoft Academic Search

Ultra Wide Band technology has attracted a lot of attention recently as a viable solution for high data rate, low power, short-range wireless link. The growing multi-media home networking is demanding more bandwidth and wireless throughput has become a bottleneck for high quality multi-media services. With the maximum data rate above 100 Mbps, UWB is a perfect solution for such

C. Duan; G. Pekhteryev; J. Fang; Y P Nakache; J. Zhang; K. Tajima; Y. Nishioka; H. Hirai

2006-01-01

358

Dielectric-EBG covered conical antenna for UWB applications  

Microsoft Academic Search

Purpose – The purpose of this paper is to investigate of the ultra-wide band (UWB) characteristics of a conical antenna covered by an electromagnetic band-gap (EBG) structure composed of alternating high- and low-permittivity dielectric spherical shells. Design\\/methodology\\/approach – A finite difference time domain in spherical coordinates is implemented in order to characterize the antenna's performance and waveform fidelity in case

George S. Kliros; George Kyritsis; Dimos Touzloudis

2010-01-01

359

An ultrawideband (UWB) switched-antenna-array radar imaging system  

Microsoft Academic Search

A low-cost ultrawideband (UWB), 1.926-4.069 GHz, phased array radar system is developed that requires only one exciter and digital receiver that is time-division-multiplexed (TDM) across 8 receive elements and 13 transmit elements, synthesizing a fully populated 2.24 m long (?\\/2 element-to-element spacing) linear phased array. A 2.24 m linear phased array with a 3 GHz center frequency would require 44

Gregory L. Charvat; Leo C. Kempel; E. J. Rothwell; Christopher M. Coleman; Eric L. Mokole

2010-01-01

360

Performance optimization of TH-UWB system in multipath channel  

Microsoft Academic Search

In this paper, we propose a method to minimize the Multi-User Interference (MUI) caused by multiple access (MA) in a Time Hopping Ultra Wide Band (TH-UWB) system with line-of-sight (LOS) multi-path channel in a residential environment IEEE 802.15.4a channel model. We considered synchronous case over an Additive White Gaussian Noise channel (AWGN). The problem is formulated as a combinatorial optimization

Naanaa Anis; Safya Belghith

2010-01-01

361

Energy detection under narrowband interference in UWB systems  

Microsoft Academic Search

Non-coherent UWB receivers are cost-effective and robust against multipath propagation. However the analog-front end of such receivers is highly susceptible to narrowband interference (NBI), which could undermine the overall performance of the receiver. To cope with this, we propose a multichannel energy detection scheme. The receiver uses a bank of correlators with different short delays to capture and suppress the

Yohannes D. Alemseged; Klaus Witrisal

2007-01-01

362

Asynchronous pipelined MB-OFDM UWB transceiver on FPGA  

Microsoft Academic Search

The key requirement of 200 Mbps MB-OFDM UWB wireless system is that the OFDM block which is a 128 point FFT\\/IFFT processor has to operate at 528 MHz. The same way, a 64 state, rate-1\\/3 Viterbi decoder block is needed but this has to operate at 125 MHz. Novel schemes are essential for achieving these speeds on FPGAs. In this

M. Santhi; Sowjanya Tungala; C. Balakrishna; G. Lakshminarayanan

2009-01-01

363

UWB transmitted reference signaling schemes - part I: performance analysis  

Microsoft Academic Search

Transmitted-reference (TR) signaling, in conjunction with an autocorrelation receiver (AcR), offers a low-complexity alternative to Rake reception. Due to its simplicity, there is renewed interest in TR signaling for ultrawide bandwidth (UWB) systems. Different variations of TR signaling have been proposed and investigated, including differential TR (DTR) signaling and noise averaging at the AcR. This paper provides performance analysis of

Tony Q. S. Quek; Moe Z. Win; Davide Dardari

2005-01-01

364

A 0.13 ?m CMOS UWB transceiver  

Microsoft Academic Search

A direct-conversion UWB transceiver for mode 1 OFDM applications employs three resonant networks and three PLLs. Designed in a 0.13 ?m CMOS technology, the transceiver provides a total gain in the range of 69 to 73 dB, an NF in the range of 5.5 to 8.4 dB across three bands, and a TX P1dB of -10 dBm. The circuit consumes

B. Razavi; T. Aytur; Fei-Ran Yang; Ran-Hong Yan; Han-Chang Kang; Cheng-Chung Hsu; Chao-Cheng Lee

2005-01-01

365

Optimized Demodulation for MAI Resilient UWB W-PAN Receivers  

Microsoft Academic Search

We design new receiver structures suited for the ultra wide band (UWB) standard IEEE 802.15.4a. The design objective is a receiver robust to multiuser access interference (MAI), which is a particular severe impairment in simple wireless personal area networks (W-PAN). Unlike most approaches of the literature that focus on the optimisation of decoding, we jointly optimize both demodulation and decoding,

Tomaso Erseghe; Stefano Tomasin

2008-01-01

366

Ultrawideband synthetic vision sensor for airborne wire detection  

Microsoft Academic Search

A low cost, miniature ultra wideband (UWB) radar has demonstrated the ability to detect suspended wires and other small obstacles at distances exceeding several hundred feet using an average output power of less than 10 microwatts. Originally developed as a high precision UWB radar altimeter for the Navy's Program Executive Office for Unmanned Aerial Vehicles and Cruise Missiles, an improved

Robert J. Fontana; J. F. Larrick; Jeffrey E. Cade; Eugene P. Rivers

1998-01-01

367

Configurable Conformal Impulse Receive Antenna.  

National Technical Information Service (NTIS)

Among leading-edge research concerns in ultra-wideband (UWB) radiofrequency (RF) methods, it has recently become important to devise antennas to satisfy the following conditions as much as possible: (a) be UWB responsive; (b) be preserving of impulse wave...

G. H. Kirk

2005-01-01

368

Data gathering in ultra wide band based wireless sensor networks using a mobile node  

Microsoft Academic Search

Ultra-wideband (UWB) communications is receiving significant attention recently due to its high data rates and low power, low interference transmission. This paper considers the issue of utilizing these advantages of UWB to design improved Wireless Sensor Networks (WSNs). In particular, we consider data gathering in wireless sensor networks using a mobile node for data collection. We first propose a network

Deepak Bote; Krishna M. Sivalingam; Prathima Agrawal

2007-01-01

369

A 3.1–4.8 GHz transmitter with a high frequency divider in 0.18 ?m CMOS for OFDM-UWB  

Microsoft Academic Search

A fully integrated low power RF transmitter for a WiMedia 3.1–4.8 GHz multiband orthogonal frequency division multiplexing ultra-wideband system is presented. With a separate transconductance stage, the quadrature up-conversion modulator achieves high linearity with low supply voltage. The co-design of different resonant frequencies of the modulator and the differential to single (D2S) converter ensures in-band gain flatness. By means of

Zheng Renliang; Ren Junyan; Li Wei; Li Ning

2009-01-01

370

SEMICONDUCTOR INTEGRATED CIRCUITS: A 3.1-4.8 GHz transmitter with a high frequency divider in 0.18 mum CMOS for OFDM-UWB  

Microsoft Academic Search

A fully integrated low power RF transmitter for a WiMedia 3.1-4.8 GHz multiband orthogonal frequency division multiplexing ultra-wideband system is presented. With a separate transconductance stage, the quadrature up-conversion modulator achieves high linearity with low supply voltage. The co-design of different resonant frequencies of the modulator and the differential to single (D2S) converter ensures in-band gain flatness. By means of

Zheng Renliang; Ren Junyan; Li Wei; Li Ning

2009-01-01

371

A low noise CMOS RF front-end for UWB 6-9 GHz applications  

NASA Astrophysics Data System (ADS)

An integrated fully differential ultra-wideband CMOS RF front-end for 6-9 GHz is presented. A resistive feedback low noise amplifier and a gain controllable IQ merged folded quadrature mixer are integrated as the RF front-end. The ESD protected chip is fabricated in a TSMC 0.13 ?m RF CMOS process and achieves a maximum voltage gain of 23-26 dB and a minimum voltage gain of 16-19 dB, an averaged total noise figure of 3.3-4.6 dB while operating in the high gain mode and an in-band IIP3 of -12.6 dBm while in the low gain mode. This RF front-end consumes 17 mA from a 1.2 V supply voltage.

Feng, Zhou; Ting, Gao; Fei, Lan; Wei, Li; Ning, Li; Junyan, Ren

2010-11-01

372

Integrated cm- and mm-Wave UWB Transceiver for M-Sequence-Based Sensors  

NASA Astrophysics Data System (ADS)

An integrated, completely balanced broadband transceiver front end for operation in the cm- and mm-wave range is presented. It is compatible with our ultra-wideband M-sequence baseband system. The transceiver front end is based on the application of specific integrated circuits (ASICs) designed for a 0.25 ?m SiGe process with f T/f max = 180/220 GHz. To achieve an optimum reasonable compromise between flexibility, complexity, and the system performance, we decided to design three different front-end ASICs - an up-converter, a down-converter, and a LO unit. All of them are mounted on an RF-LTCC (low-temperature co-fired ceramics) test board for optimal RF wiring. The final goal is to provide an integrated transceiver module which covers the whole RF part from the antennas to the IF stage. First measurement results will be shown.

Kmec, M.; Müller, J.; Rauschenbach, P.; Rentsch, S.; Sachs, J.; Yang, B.

373

Evaluation of Electromagnetic Interference Between UWB System and Wireless LAN Using a GTEM Cell  

Microsoft Academic Search

We propose the method of the interference evaluation between the UWB and the wireless LAN by using the GTEM cell that can test the receiver with the antenna built-in type in the paper. We show that the GTEM cell can be used in the frequency band of DS-UWB by the evaluation of the frequency response. The interference evaluation was conducted

Masashi Yamada; Masamitsu Tokuda; Shinobu Ishigami; Kaoru Gotoh; Yasushi Matsumoto

2007-01-01

374

Performance Analysis of FMCW-UWB Radar for Oil Tank Level Gauge  

Microsoft Academic Search

This paper analyzes the detection probability of FMCW-UWB radar based on Doppler frequency and ADC bit for oil tank level gauge. The FMCW-UWB radar system consists of a transmitted part and a received part and uses an additive white Gaussian noise (AWGN) channel. The system model is verified through analysis and simulation. The performance degradation of detection does not occur

Sang-Dong Kim; Jong-Hun Lee

2011-01-01

375

A Rate Control Technology Based on RCP-LDPC Code for Cooperative Cognitive UWB System  

Microsoft Academic Search

Cooperative cognitive UWB system is one of the hottest topics in wireless communication areas. Rate control technology is the key technology of it. An algorithm of rate control using RCP-LDPC code in DF cognitive UWB systems is proposed, which comprised of grouping and selecting, and a suitable RCP-LDPC code is constructed. Simulation results show that the proposed rate control puncture

Fangni Chen

2010-01-01

376

UWB Radiowave Propagation within the Passenger Cabin of a Boeing 737-200 Aircraft  

Microsoft Academic Search

Past efforts to develop measurement-based models of the UWB propagation channel have focused on residential, office, and industrial environments. However, with its confined volume and cylindrical structure, the geometry of the passenger cabin of a jet aircraft is fundamentally different from those environments considered previously. Here, we characterize large-scale aspects of UWB propagation within the passenger cabin of a typical

James Chuang; Ni Xin; Howard Huang; Simon Chiu; David G. Michelson

2007-01-01

377

Multipath decision fusion for low complexity UWB-IR non-coherent receivers  

Microsoft Academic Search

In UWB Impulse Radio (UWB-IR), non coherent reception with energy collection might suffer from dispersive channels. This paper proposes an energy selective receiver based on a threshold device. Multipath detection decisions are weighted by a confidence coefficient and combined, following an optimum Bayesian decision rule that takes into account both multipaths and symbol coding. Simulations on realistic channels show that

Benoit Miscopein; Jean Schwoerer; Jean-Marie Gorce

2009-01-01

378

A 0.18 ?m CMOS low noise amplifier using a current reuse technique for 3.1-10.6 GHz UWB receivers  

NASA Astrophysics Data System (ADS)

A new, low complexity, ultra-wideband 3.1-10.6 GHz low noise amplifier (LNA), designed in a chartered 0.18 ?m RFCMOS technology, is presented. The ultra-wideband LNA consists of only two simple amplifiers with an inter-stage inductor connected. The first stage utilizing a resistive current reuse and dual inductive degeneration technique is used to attain a wideband input matching and low noise figure. A common source amplifier with an inductive peaking technique as the second stage achieves high flat gain and wide -3 dB bandwidth of the overall amplifier simultaneously. The implemented ultra-wideband LNA presents a maximum power gain of 15.6 dB, and a high reverse isolation of -45 dB, and good input/output return losses are better than -10 dB in the frequency range of 3.1-10.6 GHz. An excellent noise figure (NF) of 2.8-4.7 dB was obtained in the required band with a power dissipation of 14.1 mW under a supply voltage of 1.5 V An input-referred third-order intercept point (IIP3) is -7.1 dBm at 6 GHz. The chip area, including testing pads, is only 0.8 × 0.9 mm2.

Chunhua, Wang; Qiuzhen, Wan

2011-08-01

379

Ultra-Wideband Transmission Over Low Loss PCF  

Microsoft Academic Search

The explosive growth in Internet traffic will lead to a demand for greater capacity. Wavelength-division-multiplexing (WDM) transmission using a broad wavelength region is considered a promising candidate transmission technology with which to meet this demand. Photonic crystal fibers (PCF) are attractive in terms of realizing wideband WDM transmission because they have unique features that are unavailable with conventional single-mode fibers,

Kenji Kurokawa; Kazuhide Nakajima; Kyozo Tsujikawa; Takashi Yamamoto; Katsusuke Tajima

2009-01-01

380

Rectangular reconfigurable antenna (RRA) with ultra wideband tuning ability  

Microsoft Academic Search

A rectangular reconfigurable antenna (RRA) is presented in this paper. The antenna system consists of 8 rectangular radiating components functioning independently. The power radiated equation as well as the equivalent circuit for the antenna is presented in this paper. Each rectangular radiating part has its own individual substrate so as to have each radiating component function independently. The results showing

Shishir Shanker Punjala; Kia Makki

2009-01-01

381

Ultra-Wideband Direction Finding Using Fiber Optic Transversal Filters.  

National Technical Information Service (NTIS)

This report describes a wideband electro-optic direction finding (DF) processor using an array of laser diodes, an array of photodetectors, and a network of fiber optic delay lines. This DF filter offers a potential operational bandwidth in excess of 10 G...

S. A. Pappert

1987-01-01

382

Location and Navigation with Ultra-Wideband Signals.  

National Technical Information Service (NTIS)

Existing positioning and navigation applications mainly rely on GNSS. However, its application to indoor, metropolitan and heavy-foliage scenarios is significantly constrained by the satellite visibility, limited accuracy and the intensively frequency-sel...

J. Harris L. Yang

2012-01-01

383

Ultra wideband, high sensitivity magneto-optic field sensor  

NASA Astrophysics Data System (ADS)

Using the bismuth rare-earth iron garnet thick films we have demonstrated a magneto-optic (MO) field sensor. The sensor made of all dielectric materials is nearly noninvasive, and is operated at room temperature. The sensor's sensitivity is scalable; the same sensor design can be used for a low-field sensor to measure fields below nano-Tesla or for a high-field sensor to measure several hundred Tesla. The highest sensitivity that we have achieved with the sensor is about 30 pico-Tesla/(Hz)^1/2. Presently its frequency range is limited from DC to 2 GHz. We have carried out several different experiments with this sensor to explore a few interesting applications, such as electromagnetic signal interception tests over a very broad frequency range. In this presentation we will report our experimental results obtained from this MO field sensor.

Wu, Dong Ho; Garzarella, Anthony; Fratello, Vince

2012-02-01

384

Characterization of the ultra wideband body area propagation channel  

Microsoft Academic Search

Using wireless sensors placed on a person to continuously monitor health information is a promising new application. In developing these sensors, detailed knowledge of the communication channel is essential. However, there are currently very few measurements describing propagation around the body. To address this problem, we have measured electromagnetic waves traveling near the torso to derive a simple pathless law.

Andrew Fort; Claude Desset; Julien Ryckaert; Philippe De Doncker; Leo Van Biesen; Piet Wambacq

2005-01-01

385

Ultra-Wideband Signals for Target Detection in Foliage.  

National Technical Information Service (NTIS)

In this report we have demonstrated the properties of precursor-like waveforms that are important if these waveforms are to be considered for radar detection of targets embedded in foliage. These properties are: (1) Precursor- like waveforms are greatly a...

K. Ding J. K. Schindler K. T. Kim L. I. Perlovsky J. L. Poirier

2004-01-01

386

High power ultra wideband radar exotic material response  

Microsoft Academic Search

This paper is the first of two that present analytical and numerical analysis of high power and ultra wide band radars interacting with EMI and radar suppression materials. Magnetic materials are often used in isolators, thin film EMI materials and\\/or appliques. Such magnetic composites may be exposed to wide band and\\/or high power signals in operational radar systems. We describe

Rick L. Moore; John Meadors; Robert Rice

2008-01-01

387

UWB EMI To Aircraft Radios: Field Evaluation on Operational Commercial Transport Airplanes. Volume 1  

NASA Technical Reports Server (NTRS)

Ultrawideband (UWB) transmitters may soon be integrated into a wide variety of portable electronic devices (PEDs) that passengers routinely carry on board commercial airplanes. Airlines and the FAA will have difficulty controlling passenger use of UWB transmitters during flights with current airline policies and existing wireless product standards. The aeronautical community is concerned as to whether evolving FCC UWB rules are adequate to protect legacy and emerging aeronautical radio systems from electromagnetic interference (EMI) from emerging UWB products. To address these concerns, the NASA Office of Space Communications and Chief Spectrum Managers assembled a multidisciplinary team from NASA LaRC, NASA JPL, NASA ARC, FAA, United Airlines, Sky West Airlines, and Eagles Wings Inc. to carry out a comprehensive series of tests aimed at determining the nature and extent of any EMI to aeronautical communication and navigation systems from UWB devices meeting FCCapproved and proposed levels for unlicensed handheld transmitters.

Oria, A. J. (Editor); Ely, Jay J.; Martin, Warren L.; Shaver, Timothy W.; Fuller, Gerald L.; Zimmerman, John; Fuschino, Robert L.; Larsen, William E.

2005-01-01

388

Ultrawide-band electromagnetic pulses induced hypotension in rats.  

PubMed

The ultrawide-band (UWB) electromagnetic pulses are used as a new modality in radar technology. Biological effects of extremely high peak E-field, fast rise time, ultrashort pulse width, and ultrawide band have not been investigated heretofore due to the lack of animal exposure facilities. A new biological effects database is needed to establish personnel protection guidelines for these new type of radiofrequency radiation. Functional indices of the cardiovascular system (heart rate, systolic, mean, and diastolic pressures) were selected to represent biological end points that may be susceptible to the UWB radiation. A noninvasive tail-cuff photoelectric sensor sphygmomanometer was used. Male Wistar-Kyoto rats were subjected to sham exposure, 0.5-kHz (93 kV/m, 180 ps rise time, 1.00 ns pulse width, whole-body averaged specific absorption rate, SAR = 70 mW/kg) or a 1-kHz (85 kV/m, 200 ps rise time, 1.03 ns pulse width, SAR = 121 mW/kg) UWB fields in a tapered parallel plate GTEM cell for 6 min. Cardiovascular functions were evaluated from 45 min to 4 weeks after exposures. Significant decrease in arterial blood pressures (hypotension) was found. In contrast, heart rate was not altered by these exposures. The UWB radiation-induced hypotension was a robust, consistent, and persistent effect. PMID:10497968

Lu, S T; Mathur, S P; Akyel, Y; Lee, J C

1999-09-01

389

Ultrawide-band electromagnetic pulses induced hypotension in rats.  

PubMed

The ultrawide-band (UWB) electromagnetic pulses are used as a new modality in radar technology. Biological effects of extremely high peak E-field, fast rise time, ultrashort pulse width, and ultrawide band have not been investigated heretofore due to the lack of animal exposure facilities. A new biological effects database is needed to establish personnel protection guidelines for these new type of radiofrequency radiation. Functional indices of the cardiovascular system (heart rate, systolic, mean, and diastolic pressures) were selected to represent biological end points that may be susceptible to the UWB radiation. A noninvasive tail-cuff photoelectric sensor sphygmomanometer was used. Male Wistar-Kyoto rats were subjected to sham exposure, 0.5-kHz (93 kV/m, 180 ps rise time, 1.00 ns pulse width, whole-body averaged specific absorption rate, SAR = 70 mW/kg) or a 1-kHz (85 kV/m, 200 ps rise time, 1.03 ns pulse width, SAR = 121 mW/kg) UWB fields in a tapered parallel plate GTEM cell for 6 min. Cardiovascular functions were evaluated from 45 min to 4 weeks after exposures. Significant decrease in arterial blood pressures (hypotension) was found. In contrast, heart rate was not altered by these exposures. The UWB radiation-induced hypotension was a robust, consistent, and persistent effect. PMID:10073476

Lu, S T; Mathur, S P; Akyel, Y; Lee, J C

390

Transient Capacity Evaluation of UWB Ad Hoc Network with MIMO  

Microsoft Academic Search

\\u000a In this paper we evaluate capacity of UWB ad hoc network which is based on direct-sequence code division multiple access(DS-CDMA)\\u000a with multiple-input, multiple-output(MIMO). We propose an efficient and simple connection admission control(CAC) algorithm\\u000a using transient quality of service(QoS) measure. The transient outage probability, one of the QoS measures, will be estimated\\u000a using the Chernoff bound approach and the central limit

Cheol Yong Jeon; Yeong Min Jang

2005-01-01

391

Diffraction of ultrawide band radar pulses  

NASA Astrophysics Data System (ADS)

Diffraction plays an important role in determining the RCS of a body. At some frequencies, typically low frequencies, diffraction can dominate the scattering process. This work examines the effects of diffraction on ultrawide band (UWB) radar pulses. We measured the RCS of three different size square aluminum plates using a UWB pulse and broadband sampling oscilloscope. We used a bistatic measurement configuration with a bistatic angle of 10.58 deg. The plates were rotated from -90 deg to +90 deg in 2 deg increments (angles relative to the center line of the bistatic configuration). Diffraction patterns for each plate are plotted and the time domain wave forms are analyze. We find that the smallest plate has a significant amount of diffracted energy even in its specular reflection lobe. The largest plate is relatively free from diffraction. Travelling waves and late time resonances are observed for the plates.

Madonna, R. G.; Scheno, P. J.; Scannapieco, J.

1992-05-01

392

Estimating the breast surface using UWB microwave monostatic backscatter measurements.  

PubMed

This paper presents an algorithm for estimating the location of the breast surface from scattered ultrawideband (UWB) microwave signals recorded across an antenna array. Knowing the location of the breast surface can improve imaging performance if incorporated as a priori information into recently proposed microwave imaging algorithms. These techniques transmit low-power microwaves into the breast using an antenna array, which in turn measures the scattered microwave signals for the purpose of detecting anomalies or changes in the dielectric properties of breast tissue. Our proposed surface identification algorithm consists of three procedures, the first of which estimates M points on the breast surface given M channels of measured microwave backscatter data. The second procedure applies interpolation and extrapolation to these M points to generate N > M points that are approximately uniformly distributed over the breast surface, while the third procedure uses these N points to generate a 3-D estimated breast surface. Numerical as well as experimental tests indicate that the maximum absolute error in the estimated surface generated by the algorithm is on the order of several millimeters. An error analysis conducted for a basic microwave radar imaging algorithm (least-squares narrowband beamforming) indicates that this level of error is acceptable. A key advantage of the algorithm is that it uses the same measured signals that are used for UWB microwave imaging, thereby minimizing patient scan time and avoiding the need for additional hardware. PMID:18232368

Winters, David W; Shea, Jacob D; Madsen, Ernest L; Frank, Gary R; Van Veen, Barry D; Hagness, Susan C

2008-01-01

393

A novel design UWB antenna having band notch characteristics  

NASA Astrophysics Data System (ADS)

A Novel Design using two feed structure for Ultra Wide Band Antenna with band notch characteristics is being presented in this paper. The simulated antenna so designed have a compact small physical size of 16 mm (L) × 20 mm (W) × 1.6 mm (h) of the overall design with the patch size as 11.86 mm (L) × 8.96 mm (W). The antenna is designed to simulate at 10 GHz. The substrate used is Duroid™ with a relative permittivity of (?r=2.2) and the return loss so measured is calculated below -10 dB for the range 3.1-19.53 GHz with band notching in the frequency band 5.1-5.8 GHz (i.e. WLAN). To achieve such UWB antenna with band notch, the three concepts used are introduced, the first one is using two feeding structure, the second one is using steps at the bottom of the patch, introducing steps at the bottom centre of the patch for band notching. The final impedance bandwidth so measured is 145 % which is a very high bandwidth so obtained. The optimized antenna designed can be used in any of the wireless device for UWB applications.

Gour, Ajay S.; Mathur, Dhirendra

2013-01-01

394

Pulse Design for Time Reversal Method as Applied to Ultrawideband Microwave Breast Cancer Detection: A Two-Dimensional Analysis  

Microsoft Academic Search

We conduct a two-dimensional study of pulse design for electromagnetic time-reversal (TR) imaging as applied to ultrawideband (UWB) breast cancer detection. We consider the situation when a tumor located in the human breast is surrounded by a large number of small tissue inhomogeneities that create strong signal clutter. When applying the TR algorithm, the excitation pulse should be properly designed

Yifan Chen; Erry Gunawan; Kay Soon Low; Shih-Chang Wang; Yongmin Kim; Cheong Boon Soh

2007-01-01

395

High-Voltage-Gain CMOS LNA For 6–8.5GHz UWB Receivers  

Microsoft Academic Search

The design of a fully integrated CMOS low noise amplifiers (LNA) for ultra-wide-band (UWB) integrated receivers is presented. An original LC input matching cell architecture enables fractional bandwidths of about 25%, with practical values, that match the new ECC 6-8.5-GHz UWB frequency band. An associated design method which allows low noise figure and high voltage gain is also presented. Measurements

Marc Battista; Jean Gaubert; Matthieu Egels; Sylvain Bourdel; HervÉ Barthelemy

2008-01-01

396

A Novel Zonal UWB Receiver Structure with Improved Performance in Multiple Access Interference  

Microsoft Academic Search

A novel ultra-wide bandwidth receiver structure is proposed for time-hopping ultra-wide bandwidth wireless signal detection in multiple access interference channels. In ideal free-propagation channels, the zonal receiver always meets or outperforms the conventional matched filter UWB receiver, the recently proposed soft-limiting UWB receiver and its enhanced version, the adaptive threshold soft-limiting ultra-wide bandwidth receiver. A new Rake receiver design based

Hua Shao; Norman C. Beaulieu

2007-01-01

397

Normalised Least Mean-Square Aided Decision-Directed Adaptive Detection in Hybrid Direct-Sequence Time-Hopping UWB Systems  

Microsoft Academic Search

In this contribution decision-directed adaptive detection scheme based on normalised least mean-square (DD\\/NLMS) principles is proposed and investigated for the hybrid direct- sequence time-hopping ultrawide bandwidth (DS-TH UWB) system. The bit-error-rate (BER) performance of the hybrid DS-TH UWB system is investigated when communicating over the UWB channels modelled by the Saleh-Valenzuela (S-V) channel model. Since both the pure DS-UWB and

Qasim Zeeshan Ahmed; Lie-liang Yang

2008-01-01

398

Investigations into SUB-NS Pulse Generation Using Ferrite-Loaded Coaxial Lines.  

National Technical Information Service (NTIS)

Systems such as Pockels Cell drivers and UWB radar require electrical pulses of less than 200 ps rise-time and amplitude of 10 kV or greater into 50 ohms. Desired p.r.f.'s may be 50 kHz or higher in burst mode. The output rise-time of high power and p.r.f...

H. R. Bolton J. E. Dolan A. J. Shapland D. M. Parkes K. Trafford

1995-01-01

399

A switching-band CMOS low-noise amplifier for 6–11GHz MB-OFDM UWB wireless radio system  

Microsoft Academic Search

This paper presents a low-power low-noise amplifier (LNA) with switching bands for MB-OFDM Group-C and Group-D ultra-wideband wireless radio system. The LNA is designed and implemented in TSMC 0.18 mum . Simulation results show that power gain of 12.4 dB, input and output matching lower then - 8.5 dB and - 14.5 dB, and a minimum NF of 4.0 dB

Zhe-Yang Huang; Che-Cheng Huang

2007-01-01

400

Electromagnetic and thermal effects of IR-UWB wireless implant systems on the human head.  

PubMed

The usage of implanted wireless transmitting devices inside the human body has become widely popular in recent years. Applications such as multi-channel neural recording systems require high data rates in the wireless transmission link. Because of the inherent advantages provided by Impulse-Radio Ultra Wide Band (IR-UWB) such as high data rate capability, low power consumption and small form factor, there has been an increased research interest in using IR-UWB for bio-medical implant applications. Hence it has become imperative to analyze the electromagnetic effects caused by the use of IR-UWB when it is operated in or near the human body. This paper reports the electromagnetic effects of head implantable transmitting devices operating based on Impulse Radio Ultra Wide Band (IR-UWB) wireless technology. Simulations illustrate the performance of an implantable UWB antenna tuned to operate at 4 GHz with an -10dB bandwidth of approximately 1 GHz when it is implanted in a human head model. Specific Absorption Rate (SAR), Specific Absorption (SA) and temperature increase are analyzed to compare the compliance of the transmitting device with international safety regulations. PMID:24110902

Thotahewa, Kasun M S; Redoute, Jean-Michel; Yuce, Mehmet R

2013-01-01

401

Wearable system-on-a-chip UWB radar for contact-less cardiopulmonary monitoring: present status.  

PubMed

The present status of the project aimed at the realization of an innovative wearable system-on-chip UWB radar for the cardiopulmonary monitoring is presented. The overall system consists of a wearable wireless interface including a fully integrated UWB radar for the detection of the heart beat and breath rates, and a IEEE 802.15.4 ZigBee low-power radio interface. The principle of operation of the UWB radar for the monitoring of the heart wall is summarized. With respect to the prior art, this paper reports the results of the experimental characterization of the intra-body channel loss, which has been carried out successfully in order to validate the theoretical model employed for the radar system analysis. Moreover, the main building blocks of the radar have been manufactured in 90 nm CMOS technology by ST-Microelectronics and the relevant performance are resulted in excellent agreement with those expected by post-layout simulations. PMID:19163907

Zito, D; Pepe, D; Mincica, M; Zito, F; De Rossi, D; Lanata, A; Scilingo, E P; Tognetti, A

2008-01-01

402

Smart container UWB sensor system for situational awareness of intrusion alarms  

DOEpatents

An in-container monitoring sensor system is based on an UWB radar intrusion detector positioned in a container and having a range gate set to the farthest wall of the container from the detector. Multipath reflections within the container make every point on or in the container appear to be at the range gate, allowing intrusion detection anywhere in the container. The system also includes other sensors to provide false alarm discrimination, and may include other sensors to monitor other parameters, e.g. radiation. The sensor system also includes a control subsystem for controlling system operation. Communications and information extraction capability may also be included. A method of detecting intrusion into a container uses UWB radar, and may also include false alarm discrimination. A secure container has an UWB based monitoring system

Romero, Carlos E.; Haugen, Peter C.; Zumstein, James M.; Leach, Jr., Richard R.; Vigars, Mark L.

2013-06-11

403

A monolithic RF transceiver for DC-OFDM UWB  

NASA Astrophysics Data System (ADS)

This paper presents a first monolithic RF transceiver for DC-OFDM UWB applications. The proposed direct-conversion transceiver integrates all the building blocks including two receiver (Rx) cores, two transmitter (Tx) cores and a dual-carrier frequency synthesizer (DC-FS) as well as a 3-wire serial peripheral interface (SPI) to set the operating status of the transceiver. The ESD-protected chip is fabricated by a TSMC 0.13-?m RF CMOS process with a die size of 4.5 × 3.6 mm2. The measurement results show that the wideband Rx achieves an NF of 5-6.2 dB, a max gain of 76-84 dB with 64-dB variable gain, an in-/out-of-band IIP3 of -6/+4 dBm and an input loss S11 of < -10 in all bands. The Tx achieves an LOLRR/IMGRR of -34/-33 dBc, a typical OIP3 of +6 dBm and a maximum output power of -5 dBm. The DC-FS outputs two separate carriers simultaneously with an inter-band hopping time of < 1.2 ns. The full chip consumes a maximum current of 420 mA under a 1.2-V supply.

Yunfeng, Chen; Wei, Li; Haipeng, Fu; Ting, Gao; Danfeng, Chen; Feng, Zhou; Deyun, Cai; Dan, Li; Yangyang, Niu; Hanchao, Zhou; Ning, Zhu; Ning, Li; Junyan, Ren

2012-02-01

404

Brillouin precursor waveforms pertaining to UWB noise radar signals propagating through dispersive media  

NASA Astrophysics Data System (ADS)

The electromagnetic (EM) waves propagating through causal, linear, and lossy dispersive media (soil, foliage, plasma, water, biological tissue, etc.), experience frequency-dependent attenuation and phase distortion. This has assumed significant importance for systems operating with ultrawideband (UWB) spectrum. This paper analyzes the dynamical evolution of UWB noise radar signals through dispersive media. The effects on the signal propagation due to the evolution of the Brillouin precursor through dispersive media are discussed. The evolving waveforms are then compared with the Brillouin precursor due to rectangular sine-modulated deterministic signals. The advantages of random noise waveforms through dispersive media are also discussed.

Dawood, M.; Alejos, A. V.

2011-05-01

405

Comparison of the relative merits for target recognition by ultrawideband radar based on emitted impulse or step-frequency wave  

NASA Astrophysics Data System (ADS)

The feasibility of ultra-wideband (UWB) radar systems for extracting signature information useful for target recognition purposes has been demonstrated previously. An UWB radar system emits either an extremely short pulse, impulse, or a frequency modulated signal (e.g., sweep or step-frequency). The frequency content of the emitted signals is designed to match the size and kind of typical targets and environments. We study the performance of two different radar systems, each intended for use as a ground penetrating radar (GPR). These systems are an impulse radar and a stepped-frequency continuous-wave radar. The frequency content of the emitted pulses is about 300 - 3,000 MHz with both systems. The same antenna system consisting of two crossed dipoles (transmitting and receiving) is used with both radar systems and it is directed upward in an outdoor setup. The targets are metal spheres of two sizes and each of them is placed above the antenna system on a thick foam plate made of polystyrene, which is virtually transparent for microwaves. Backscattered echoes from each target are analyzed in the frequency domain using traditional Fourier transforms and in the joint time- frequency domain using Wigner distributions (WD). The measured and digitally processed waveforms are then compared with theoretical predictions and the relative merits of the two UWB radar systems are evaluated. The results of our investigation serve to assess the best choice of GPR system for extracting discriminating target signature information.

Strifors, Hans C.; Friedmann, Anders; Abrahamson, Steffan; Gaunaurd, Guillermo C.

2000-08-01

406

Radar-based breast cancer detection experiment with synthetic breast phantom using model subtraction method  

Microsoft Academic Search

Ultra-wideband (UWB) antennas such as compact vivaldi antennas has been applied to the simulation experiment of breast cancer detection. A commercial-made synthetic breast phantom model is used in our experiment. We can find that it is effective to detect the breast cancer tumor using vegetable gelatin model subtraction method. Image reconstructions of the breast models using reflection data have been

Dan Zhang; Atsushi Mase

2011-01-01

407

PSO-based time-domain antenna synthesis for enhanced UWB communication systems  

Microsoft Academic Search

In this paper, an approach for the synthesis of antenna systems suitable for UWB communication applications has been presented. The final antenna geometry is obtained by means of a PSO aimed at fitting a set of time domain requirements. Such requirements allow the radiating system to have an high efficiency, distortionless properties, and omnidirectional radiation patterns over the whole frequency

L. Lizzi; F. Viani; P. Rocca; A. Massa

2009-01-01

408

Transmitting spectrum control by band pass tapered slot antenna on UWB-IR application  

Microsoft Academic Search

This paper describes compatibility between EIRP mask by FCC and radiating spectrum using band pass tapered slot antenna (BPTSA) on UWB impulse radio (IR) application. The study proposes some techniques to add band pass characteristic on the antenna and considers the mask compatibility by actual signal transmitting and receiving. We focus the cut off characteristic in the higher frequency region

Akinori Matsui; Yasuaki Kanda; Takeshi Suzuki; Masanori Hanawa; Kazuhiko Nakamura; Kohei Mori

2009-01-01

409

Analytic edge smoothing for planar UWB circular monopole antennas fed with coplanar waveguides  

Microsoft Academic Search

This paper presents a methodology to improve the performance of an UWB circular monopole antenna fed with a coplanar waveguide by coupling the waveguide slowly into the radiating element using a pre-defined curve that satisfies boundary conditions on the contour and its derivatives. The resulting antenna is modelled in Matlab and then transferred to CAD programs for simulation and manufacture

J. A. Gomez; G. Brooker

2010-01-01

410

Applications of high and low data rate UWB technology in public transportation  

Microsoft Academic Search

This abstract describes a series of possible applications of the ultra wide band wireless technology in public transportation environment. Application scenarios for both the high data rate technology based on WiMedia and the low data rate technology based on impulse radio are presented, indicating the specific advantages provided by UWB in comparison to other narrow band wireless standards. The work

Sergio Bovelli; Frank Leipold; Wolfgang Fischer

2009-01-01

411

Signal processing for through wall moving target tracking by M-sequence UWB radar  

Microsoft Academic Search

In this paper, through wall moving target tracking by UWB radar is described as a complex process with all required phases of radar signal processing. For particular phases of that process, i.e. for raw radar data preprocessing, background subtraction, detection, trace estimation, localization and tracking itself, the phase significance and its corresponding representative methods are outlined. The complete process is

J. Rovnakova; M. Svecova; D. Kocur; Trung Thanh Nguyen; J. Sachs

2008-01-01

412

UWB, Multi-sensors and Wifi-Mesh based precision positioning for urban rail traffic  

Microsoft Academic Search

Precision positioning for moving targets is the key issue in urban rail traffic safety assurance and operational energy saving. Precision vehicle positioning can improve transportation capacity. Meanwhile, personnel tracking can enhance daily operations as well as rescue capabilities in the event an accident or emergency. This paper discusses the development of precision positioning solution based on UWB, Multi-sensors and Wi-Fi

Lin Hui; Ye Lei; Wang Yuanfei

2010-01-01

413

A UWB imaging system to detect early breast cancer in heterogeneous breast phantom  

Microsoft Academic Search

This paper presents an experimental early breast cancer detection system in terms of heterogeneous breast phantom. The system consists of commercial Ultrawide-Band (UWB) transceivers and our developed Neural Network (NN) based Pattern Recognition (PR) software for imaging. A simple way to construct cancer- tissue and heterogeneous breast phantom using available low cost materials and their mixtures is also proposed here.

Saleh Alshehri; Adznan Jantan; R. S. A. Raja Abdullah; Rozi Mahmud; Sabira Khatun; Zaiki Awang

2011-01-01

414

Integrated transceivers for UWB breast cancer imaging: Architecture and circuit constraints  

Microsoft Academic Search

We present a behavioral analysis of two different transceiver architectures for UWB breast cancer imaging employ- ing a SFCW radar system. A mathematical model of the direct conversion and super heterodyne architectures together with a numerical breast phantom are developed. FDTD simulations data are used on the behavioral model to investigate the limits of both architectures from a circuit-level point

Matteo Bassi; Andrea Bevilacqua; Andrea Gerosa; Andrea Neviani

2011-01-01

415

Study of a printed circular disc monopole antenna for UWB systems  

Microsoft Academic Search

This paper presents a study of a novel monopole antenna for ultrawide-band (UWB) applications. Printed on a dielectric substrate and fed by a 50 ? microstrip line, a planar circular disc monopole has been demonstrated to provide an ultra wide 10 dB return loss bandwidth with satisfactory radiation properties. The parameters which affect the performance of the antenna in terms

Jianxin Liang; Choo C. Chiau; Xiaodong Chen; Clive G. Parini

2005-01-01

416

Design of a compact band-notched antenna for ultrawideband communication  

Microsoft Academic Search

A compact printed ultra-wideband (UWB) antennas with band-notched characteristic of size 30 mm times 35 mm are presented. The two designs are presented, the first antenna is designed to cover the Federal Communication Commission (FCC) bandwidth for UWB applications (3.1 - 10.6 GHz) and the second antenna is designed to cover the frequency band from 3 - 17 GHz. The

N. H. M. Sobli; H. E. Abd-El-Raouf

2008-01-01

417

Adaptive target detection in foliage-penetrating SAR images using alpha-stable models  

Microsoft Academic Search

Detecting targets occluded by foliage in foliage-penetrating (FOPEN) ultra-wideband synthetic aperture radar (UWB SAR) images is an important and challenging problem. Given the different nature of target returns in foliage and nonfoliage regions and very low signal-to-clutter ratio in UWB imagery, conventional detection algorithms fail to yield robust target detection results. A new target detection algorithm is proposed that (1)

Amit Banerjee; Philippe Burlina; Rama Chellappa

1999-01-01

418

Design and Performance of Carrier-Based DS-SS Systems on IEEE 802.15.3a UWB Channels  

Microsoft Academic Search

A set of physical layer specifications is provided for a single-band and a dual-band UWB system. Both systems fulfill the FCC regulations on UWB devices. Only the single- band system fulfills the physical layer requirements from IEEE 802.15.3a. The single-band system gives reliable communication, i.e., a 90th-percentile PER equal to 8% for 1024 payload bytes, at 110 Mbps with a

Matts-Ola Wessman; Arne Svensson; Erik Agrell

2006-01-01

419

MB-OFDM UWB signal co-transmission with WCDMA, WLAN and GSM over multi-mode radio-over-fiber  

Microsoft Academic Search

In this paper, the performance of Multiband - Orthogonal Frequency Division Multiplexing (MB-OFDM) Ultra WideBand (UWB) signal over a multimode fiber based radio-over-fiber (ROF) link is discussed. Co-transmission of UWB signals with other wireless signal standards including W-CDMA (2.15 GHz), WLAN802.11a\\/g, and GSM (1.8 GHz) are considered. Based on the measurement results, it has been shown that UWB signals can

Yong-Xin Guo; Viet Hung Pham; Ming-Li Yee; Ling Chuen Ong

2009-01-01

420

Simulation and signal processing of through wall UWB radar for human being's periodic motions detection  

NASA Astrophysics Data System (ADS)

The human's Micro-Doppler signatures resulting from breathing, arm, foot and other periodic motion can provide valuable information about the structure of the moving parts and may be used for identification and classification purposes. In this paper, we carry out simulate with FDTD method and through wall experiment with UWB radar for human being's periodic motion detection. In addition, Advancements signal processing methods are presented to classify and to extract the human's periodic motion characteristic information, such as Micro-Doppler shift and motion frequency. Firstly, we apply the Principal Component Analysis (PCA) with singular value decomposition (SVD) to denoise and extract the human motion signal. Then, we present the results base on the Hilbert-Huang transform (HHT) and the S transform to classify and to identify the human's micro-Doppler shift characteristics. The results demonstrate that the combination of UWB radar and various processing methods has potential to detect human's Doppler signatures effectively.

Li, Jing; Liu, Fengshan; Xu, Penglong; Zeng, Zhaofa

2013-05-01

421

UWB multipath channel model based on time-domain UTD technique  

Microsoft Academic Search

In this paper, we develop a deterministic UWB multipath channel model based on time-domain uniform geometrical theory of diffraction (TD-UTD) technique. The solution includes the three basic ray mechanisms of geometrical optics (GO) and UTD, i.e., directed ray, multireflected rays from lossy surfaces, and diffracted ray from lossy edge. Since the analysis is conducted in time-domain electromagnetic field, unlike statistical

Richard Yao; Grace Gao; Zhengqi Chen; Wenwu Zhu

2003-01-01

422

A parametric UWB propagation channel estimation and its performance validation in an anechoic chamber  

Microsoft Academic Search

This paper presents an ultrawide-band (UWB) channel sounding scheme with a parametric channel estimation to seek accurate probing of the propagation channel. The channel sounder consists of a vector network analzer and synthetic array to measure spatial transfer functions. The measured data are then applied to a maximum-likelihood (ML)-based estimator. The concepts implemented in the ML-based parametric channel estimation are:

Katsuyuki Haneda; Jun-Ichi Takada; Takehiko Kobayashi

2006-01-01

423

Design and implementation of UWB CMOS LC filters LNA for carrier less impulse radio receivers  

Microsoft Academic Search

The design and the implementation of Ultra-wide-band (UWB) CMOS LC filter LNA for Ultra Wide Band carrier less Impulse Radio\\u000a receivers is presented. Architectures for both single ended and differential ended LNA are proposed for small fractional bandwidths\\u000a such as the ECC frequency band and for large fractional bandwidths such as FCC frequency band. Simple guidelines to achieve\\u000a large voltage

Marc Battista; Jean Gaubert; Amir Fanei; Yannick Bachelet; Matthieu Egels; Philippe Pannier; Sylvain Bourdel; Hervé Barthélémy; Gilles Bas

2010-01-01

424

Modal Analysis and Design of Band-Notched UWB Planar Monopole Antennas  

Microsoft Academic Search

The theory of characteristic modes is proposed for the analysis of simple band-notched UWB planar monopole antennas, since the information provided by these real modes (i.e. resonant frequency and radiating bandwidth) provides a very interesting physical insight into the radiation phenomena taking place in this type of antennas. Such an in-depth understanding paves the way for the proposal of novel

Eva Antonino-Daviu; Marta Cabedo-Fabrés; Miguel Ferrando-Bataller; Vicent Miquel Rodrigo Penarrocha

2010-01-01

425

CFAR detectors for through wall tracking of moving targets by M-sequence UWB radar  

Microsoft Academic Search

In this paper different CFAR detectors for detection of multiple targets for UWB radar system will be described. In this paper, the cell averaging CFAR (CA-CFAR) cell averaging with greatest of (CAGO-CFAR) and ordered statistics CFAR (OS-CFAR) will be represented. The detectors outputs will be illustrated and compared. The properties of all detectors will be illustrated by real radar signal

Daniel URDZÍK; D. Kocur

2010-01-01

426

Calibration of the mono-static stepped-frequency GPR with a Vivaldi UWB antenna  

Microsoft Academic Search

The mono-static stepped-frequency ground penetrating radar (GPR) with a Vivaldi ultra-wide band (UWB) antenna was used to non-destructive estimate the parameters (permittivity, conductivity and thickness) of each layer of a stratified subsurface medium. In this realization, a calibration procedure is necessary. This paper introduces the principle and the implementation of this calibration. The non-directive property of the Vivaldi antenna makes

Faming Liu

2008-01-01

427

Initial timing acquisition for asynchronous DS-UWB transmissions by burst synchronization signal  

Microsoft Academic Search

We consider the initial timing acquisition for asynchronous DS-UWB transmissions in a distributed network topology, i.e., no common timing reference and neither synchronization among terminals are provided. Thus, when an arbitrary terminal in active mode (at switch-on or after sleeping period) needs to establish communication with reachable terminals, it listens for a common synchronization signal. Such a low-duty cycle synchronization

Marco Hernandez; Ryuji Kohno

2005-01-01

428

An algorithm for estimating signal-to-noise ratio of UWB signals  

Microsoft Academic Search

Recently, ultra wide-band (UWB) wireless communication technology, which provides high data transmission rates and is capable of linearly trading off between throughput and signal-to-noise ratio (SNR), has drawn much attention for short-range wireless networks. To fully exploit its desirable features and to minimize its interference with coexisting other systems requires knowledge of the SNRs at the receivers. In this paper,

Sungbin Im; Edward J. Powers

2005-01-01

429

Use of optically triggered, high gain GaAs switches for UWB pulse generation.  

National Technical Information Service (NTIS)

A high peak power impulse pulser that is controlled with high gain, optically triggered GaAs Photoconductive Semiconductor Switches (PCSS) has been constructed and tested. The system has a short 50 (Omega) line that is charged to 100 kV and discharged thr...

G. M. Loubriel F. J. Zutavern M. W. O'Malley R. R. Gallegos W. D. Helgeson

1994-01-01

430

Design of pulse waveform for waveform division multiple access UWB wireless communication system.  

PubMed

A new multiple access scheme, Waveform Division Multiple Access (WDMA) based on the orthogonal wavelet function, is presented. After studying the correlation properties of different categories of single wavelet functions, the one with the best correlation property will be chosen as the foundation for combined waveform. In the communication system, each user is assigned to different combined orthogonal waveform. Demonstrated by simulation, combined waveform is more suitable than single wavelet function to be a communication medium in WDMA system. Due to the excellent orthogonality, the bit error rate (BER) of multiuser with combined waveforms is so close to that of single user in a synchronous system. That is to say, the multiple access interference (MAI) is almost eliminated. Furthermore, even in an asynchronous system without multiuser detection after matched filters, the result is still pretty ideal and satisfactory by using the third combination mode that will be mentioned in the study. PMID:24672294

Yin, Zhendong; Wang, Zhirui; Liu, Xiaohui; Wu, Zhilu

2014-01-01

431

MAC protocols for ultra-wide-band (UWB) wireless networks: impact of channel acquisition time  

NASA Astrophysics Data System (ADS)

The upcoming Ultra-wide-band (UWB) radio technology holds great promise for revolutionizing wireless communications. UWB radios transmit using precise, very short (e.g. picosecond) impulses spread over a very large bandwidth (up to a few Ghz). The significant advantages of this technology are low-power operation, mitigated multi-path fading effects, high bit-rates and unique precise position/timing location ability. However, one of the drawbacks of this technology, in its current state, is the high channel acquisition time, i.e. the time for a transmitter and receiver to achieve bit synchronization. This tends to be quite high, of the order of a few milli-seconds. Hence, it is important for current medium access control (MAC) protocol design to consider the impact of acquisition time. In this paper, we study the performance of two standard MAC protocols - the distributed CSMA/CA protocol and the centralized TDM protocol in the context of UWB wireless local area networks. We study effects of varying packet frame sizes and packet arrival rates and present a quantification of the impact of acquisition time on overall performance.

Ding, Jin; Zhao, Li; Medidi, Sirisha R.; Sivalingam, Krishna M.

2002-10-01

432

Detection of above-ground and subsurface unexploded ordnance using ultrawideband (UWB) synthetic aperture radar (SAR) and electromagnetic modeling tools  

NASA Astrophysics Data System (ADS)

Recent development of wideband, high-resolution SAR technology has shown that detecting buried targets over large open areas may be possible. Ground clutter and soil type are tow limiting factor influencing the practicality of using wideband SAR for wide-area target detection. In particular, the presence of strong ground clutter because of the unevenness, roughness or inconsistency of the soil itself may limit the radar's capability to resolve the target from the clutter. Likewise, the soil material properties can also play a major tole. The incident wave may experience significant attenuation as the wave penetrates lossy soil. In an attempt to more fully characterize this problem, fully polarimetric ultra-wideband measurements have been taken by the US Army Research Laboratory's SAR at test sites in Yuma, Arizona, and Elgin Air Force Base, Florida. SAR images have been generated for above-ground and subsurface unexploded ordnance targets, including 155-mm shells. Additionally, a full-wave method of moments (MoM) model has been developed for the electromagnetic scattering from these same targets, accounting for the lossy nature and frequency dependency of the various soils. An approximate model based on phys9cal optics (PO) has also been developed. The efficacy of using PO in lieu of the MoM to generate the electromagnetic scattering data is examined. We compare SAR images from the measured data with images produced by the MoM and PO simulations by using a standard back-projection technique.

Sullivan, Anders J.; Damarla, Thyagaraju; Geng, Norbert; Dong, Yanting; Carin, Lawrence

2000-08-01

433

Techniques for clutter suppression in the presence of body movements during the detection of respiratory activity through UWB radars.  

PubMed

This paper focuses on the feasibility of tracking the chest wall movement of a human subject during respiration from the waveforms recorded using an impulse-radio (IR) ultra-wideband radar. The paper describes the signal processing to estimate sleep apnea detection and breathing rate. Some techniques to solve several problems in these types of measurements, such as the clutter suppression, body movement and body orientation detection are described. Clutter suppression is achieved using a moving averaging filter to dynamically estimate it. The artifacts caused by body movements are removed using a threshold method before analyzing the breathing signal. The motion is detected using the time delay that maximizes the received signal after a clutter removing algorithm is applied. The periods in which the standard deviations of the time delay exceed a threshold are considered macro-movements and they are neglected. The sleep apnea intervals are detected when the breathing signal is below a threshold. The breathing rate is determined from the robust spectrum estimation based on Lomb periodogram algorithm. On the other hand the breathing signal amplitude depends on the body orientation respect to the antennas, and this could be a problem. In this case, in order to maximize the signal-to-noise ratio, multiple sensors are proposed to ensure that the backscattered signal can be detected by at least one sensor, regardless of the direction the human subject is facing. The feasibility of the system is compared with signals recorded by a microphone. PMID:24514883

Lazaro, Antonio; Girbau, David; Villarino, Ramon

2014-01-01

434

Photoconductive Semiconductor Switches for pulsed power applications  

SciTech Connect

Photoconductive Semiconductor Switches (PCSS) are being used in, or tested for, many different pulsed power applications as diverse as ultrawideband (UWB) transmitters and high current pulsers. Some aspects of the switches that are relevant to most of the applications are: switch lifetime (longevity), switch opening time (related to the lifetime of carriers in the semiconductor), switching jitter, and the required laser energy. This paper will emphasize the results that we have obtained with Si switches for UWB applications. These include: measurement of switch longevity (a total of 80 Coulombs or 40 C/cm for a 2 cm wide switch and 18.4 Coulombs or 73 Coulombs/cm for a 0.25 cm wide switch), switching at high repetition rates (up to 540 Hz), measurement of carrier lifetime decay rates (a fast one of a few {mu}s, and a slow one of about 330 {mu}s), and measurements on the effect of neutron irradiation on carrier lifetimes. The total charge switched seems to be the highest ever reported for a PCSS. We have used these Si switches in a variety of circuits to produce: a monocycle with a period of about 10 ns corresponding to a center frequency of about 84 MHz, and ringing (many pulse) waveforms with periods of about 1 ns and 7.5 ns corresponding to center frequencies of 770 MHz and 133 MHz. We will also discuss recent studies on the switching properties of GaP.

Loubriel, G.M.; Zutavern, F.J.; Denison, G.J.; Helgeson, W.D.; McLaughlin, D.L.; O`Malley, M.W.; Buttram, M.T.

1993-08-01

435

Simulation study and experiment of breast cancer detection using an ultrashort-pulse radar  

Microsoft Academic Search

In conclusion, the simulation study using FDTD method suggests that breast cancers with less than 1 cm can be detected by an image reconstruction technique named confocal microwave imaging. Preliminary experiments of an ultrashort-pulse radar confirm that the breast cancer detection is possible by using UWB antennas, such as log-spiral and bow-tie antennas. The additional data processing should be necessary

S. Takaichi; A. Mase; Yuichiro Kogi; H. Hojo; Kang Wook Kim

2008-01-01

436

SEMICONDUCTOR INTEGRATED CIRCUITS: A high speed sampler for sub-sampling IR-UWB receiver  

NASA Astrophysics Data System (ADS)

A high speed sampler for a sub-sampling impulse radio UWB receiver is presented. In this design, the sampler uses a time-interleaved topology with a single track and hold circuit, full custom clock generator, and offset cancelled comparator. These three main blocks are also discussed and analyzed. The circuit was fabricated in 0.13 ?m CMOS technology. Measurement results indicate that the sampler achieves a maximum 3 GS/s sampling rate. The power consumption of the sampler is 27 mW under a supply voltage of 1.2 V. The total chip area including pads is 1.4 × 0.97 mm2.

Ke, Shao; Bo, Lu; Lingli, Xia; Zhiliang, Hong

2010-04-01

437

Investigation in Open Circuited Metal Lines Embedded in Defected Ground Structure and Its Applications to UWB Filters  

Microsoft Academic Search

A novel method for notch implementation in ultrawideband (UWB) bandpass filter (BPF) using open circuited metal lines embedded in a defected ground structure (DGS) is proposed. Distinct from traditional notch implementation, the proposed method uses the additional metal lines with half waveguide length embedded in defected ground structure to produce additional notch band behavior based on the DGS bandpass behavior.

Wen-Jeng Lin; Jian-Yi Li; Lih-Shan Chen; Ding-Bing Lin; Mau-Phon Houng

2010-01-01

438

Characterization of UWB Channel Impulse Responses Within the Passenger Cabin of a Boeing 737-200 Aircraft  

Microsoft Academic Search

With its confined volume, cylindrical structure and high density of seating, the passenger cabin of a typical midsize airliner is significantly different from the residential, office, outdoor and industrial environments previously considered by IEEE 802.15.4a. We have characterized the shape of the ultrawideband (UWB) channel impulse response (CIR) and the fading statistics experienced by individual multipath components (MPCs) within that

Simon Chiu; James Chuang; David G. Michelson

2010-01-01

439

Universal transmitter for wireless and optical access converged networks  

NASA Astrophysics Data System (ADS)

The integration of ultra-wideband (UWB)-over- ber into passive optical network (PON) is of great interest as it bene ts the high bandwidth capability from optical network technologies and the high exibility from wireless network technologies. The later can only be done with a reasonable cost when a universal optical transmitter, which is capable of generation both UWB and PON signals, is available. Direct modulation of semiconductor laser was demonstrated to be suitable for high bit-rate PON systems, however the generation of UWB signals by this technique is still challenging. Using the chirp properties of directly modulated semiconductor lasers, UWB signals are generated. Di erent UWB signal waveforms and polarities are obtained. The received electrical spectra conform to the requirements of indoor UWB systems.

Le, Quang T.; Küppers, Franko

2013-12-01

440

Wireless connections within spacecrafts to replace wired interface buses  

NASA Astrophysics Data System (ADS)

This paper describes measurement and characterization of radio propagation and transmission - particularly of ultra wideband (UWB) signals - within spacecrafts with a view to partly replacing on-board data buses with wireless connections. Adaption of wireless technologies within spacecraft could contribute to reduction of cable weight and resulting launching costs, and more reliable connections at rotary, moving, and sliding joints. This paper presents measurements and characteristics of radio propagation and transmission and addresses the effects of apertures perforated on the outer surface of satellites on the UWB propagation and transmission for low- and high-band UWB within a shield box. Channel responses, spatial distributions of UWB and narrowband propagation gains, delay spreads, and throughputs were derived from measurements. On the effects of apertures, the larger total area of apertures resulted in lower UWB propagation gains, shorter delay spreads, and (slightly) higher link throughput. The propagation study was followed up with experimental evaluation of UWB link throughput within a simulated spacecraft. Commercially off-the-shelf UWB devices were used in the experiments of ultra wideband technology to facilitate a high data rate (e.g. maximum of 400 Mb/s per node attained with SpaceWire, equaling the standards of a wired onboard data bus) and to reduce the fading margin.

Hamada, S.; Tomiki, A.; Toda, T.; Kobayashi, T.

441

Stealth treatment of turntable in ultra-wideband Radio Frequency Simulation System  

Microsoft Academic Search

Stealth treatment of turntable in Radio Frequency Simulation System (RFSS) with large relative bandwidth is studied in this paper. First, the shape design of three-axis turntable is optimized. Then, the surface-induced current distribution of turntable under horizontal polarization is computed and strong scattering regions are analyzed. Finally, stealth treatments as choosing absorbing materials and suitable coating methods are tested. Based

Hua Li; Jianjiang Zhou; Hanwu Zhao; Gencai Zhu

2010-01-01

442

Experimental investigation on ultra-wideband radar characteristics of coating RAM's targets  

NASA Astrophysics Data System (ADS)

A system of impulse radar is introduced, and results of an experimental investigation of a radar absorbing material (RAM) coating on the surface of metallic targets are presented. Their echo signal data are recorded, the impulse response of the targets is evaluated, and the energy of the scattering echo and the power spectral density are computed. It is shown that the ultrawideband radar is more capable than narrowband radars of mitigating the effects of RAM.

He, Jianguo; Lu, Zhongliang; Su, Yi

443

Experimental investigation on ultra-wideband radar characteristics of coating RAM's targets  

Microsoft Academic Search

A system of impulse radar is introduced, and results of an experimental investigation of a radar absorbing material (RAM) coating on the surface of metallic targets are presented. Their echo signal data are recorded, the impulse response of the targets is evaluated, and the energy of the scattering echo and the power spectral density are computed. It is shown that

Jianguo He; Zhongliang Lu; Yi Su

1992-01-01

444

Baseband, Impulse Ultra-Wideband Transceiver Front-end for Low Power Applications.  

National Technical Information Service (NTIS)

Interest in indoor wireless communications has been increasing. In addition to high throughput WLAN systems such as 802.11a/b/g/n, attention is also being focused on lower rate, short distance systems such as Bluetooth and Zigbee. These low rate radios ar...

I. D. O'Donnell

2006-01-01

445

High Voltage Properties of Insulating Materials Measured in the Ultra Wideband  

Microsoft Academic Search

Numerous dielectrics have been developed for various high-voltage high-power microwave applications. The primary goals for HPM insulation are to provide adequate insulation over the lifetime of the device, provide high dielectric strength at low volume and weight, and function with minimal maintenance and ancillary components. Current testing methods for dielectric materials are antiquated processes developed around the 60 Hz machine

M. G. Mayes; J. R. Mayes; M. B. Lara; L. L. Altgilbers

2005-01-01

446

Short-Range Ultra-Wideband Imaging with Multiple-Input Multiple-Output Arrays  

Microsoft Academic Search

Compact, cost-efficient and high-resolution imaging sensors are especially desirable in the field of short-range observation and surveillance. Such sensors are of great value in fields of security, rescue and medical applications. Systems can be formed for various practical purposes, such as detecting concealed weapons in public places, locating people inside buildings or beneath rubbles during emergency rescue, detecting landmine with

X. Zhuge

2010-01-01

447

Short range, ultra-wideband radar with high resolution swept range gate  

DOEpatents

A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with a typical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Uses of the invention include a replacement of ultrasound devices for fluid level sensing, automotive radar, such as cruise control and parking assistance, hidden object location, such as stud and rebar finding. Also, this technology can be used when positioned over a highway lane to collect vehicle count and speed data for traffic control. 14 figs.

McEwan, T.E.

1998-05-26

448

The National Geoelectromagnetic Facility - an open access resource for ultra wideband electromagnetic geophysics (Invited)  

Microsoft Academic Search

At present, the US academic community has access to two national electromagnetic (EM) instrument pools that support long-period magnetotelluric (MT) equipment suitable for crust-mantle scale studies. The requirements of near surface geophysics, hydrology, glaciology, as well as the full range of crust and mantle investigations require development of new capabilities in data acquisition with broader frequency bandwidth than these existing

A. Schultz; S. Urquhart; M. Slater

2010-01-01

449

Short range, ultra-wideband radar with high resolution swept range gate  

DOEpatents

A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with a typical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Uses of the invention include a replacement of ultrasound devices for fluid level sensing, automotive radar, such as cruise control and parking assistance, hidden object location, such as stud and rebar finding. Also, this technology can be used when positioned over a highway lane to collect vehicle count and speed data for traffic control.

McEwan, Thomas E. (Livermore, CA)

1998-05-26

450

Ultra-Wideband, Dual-Polarized, Beam-Steering P-Band Array Antenna  

NASA Technical Reports Server (NTRS)

A dual-polarized, wide-bandwidth (200 MHz for one polarization, 100 MHz for the orthogonal polarization) antenna array at P-band was designed to be driven by NASA's EcoSAR digital beam former. EcoSAR requires two wide P-band antenna arrays mounted on the wings of an aircraft, each capable of steering its main beam up to 35deg off-boresight, allowing the twin radar beams to be steered at angles to the flight path. The science requirements are mainly for dual-polarization capability and a wide bandwidth of operation of up to 200 MHz if possible, but at least 100 MHz with high polarization port isolation and low cross-polarization. The novel design geometry can be scaled with minor modifications up to about four times higher or down to about half the current design frequencies for any application requiring a dual-polarized, wide-bandwidth steerable antenna array. EcoSAR is an airborne interferometric P-band synthetic aperture radar (SAR) research application for studying two- and three-dimensional fine-scale measurements of terrestrial ecosystem structure and biomass, which will ultimately aid in the broader study of the carbon cycle and climate change. The two 2×8 element Pband antenna arrays required by the system will be separated by a baseline of about 25 m, allowing for interferometry measurements. The wide 100-to- 200-MHz bandwidth dual-polarized beams employed will allow the determination of the amount of biomass and even tree height on the ground. To reduce the size of the patches along the boresight dimension in order to fit them into the available space, two techniques were employed. One technique is to add slots along the edges of each patch where the main electric currents are expected to flow, and the other technique is to bend the central part of the patch away from the ground plane. The latter also facilitates higher mechanical rigidity. The high port isolation of more than 40 dB was achieved by employing a highly symmetrical feed mechanism for each pair of elements: three apertures coupling to the patch elements were placed along the two symmetry lines of the antenna element pair. Two apertures were used in tandem to excite two of the stacked patch elements for one polarization; the other was used to excite one element from one side and the other element from the other side, opposite in phase, taking care of the remaining polarization. The apertures narrow down to a small gap where they are excited by a crossing microstrip line to prevent any asymmetrical excitation of the two sides of the aperture gap, minimizing port-to-port coupling. Using patches that are non-planar leads to higher mechanical rigidity and smaller patch sizes to fit into the available space. Aperture coupling minimizes direct metal-to-metal connections. Using an aperture coupling feed mechanism results in a feed network for two antenna elements with a total of three feed points, plus one simple in-phase combiner to reduce it to two ports. It greatly reduces the complexity of the alternative, but more conventional, way of feeding a pair of two dual-polarized elements with high port isolation.

duToit, Cornelis

2014-01-01

451

A technique for the generation of customizable ultra-wideband pseudo-noise waveforms  

Microsoft Academic Search

Noise excitation sources in radar systems have become increasingly useful in applications requiring wideband spectral responses and covertness. However, in applications requiring spectral controllability, traditional analog noise sources prove troublesome and require additional hardware such as sets of digital filters whose own spectral characteristics must also be accounted for. In an effort to reduce these issues and increase the applications

Russell Vela; David Erisman; Ram M. Narayanan

2011-01-01

452

An Ultra-Wideband Pseudo-Noise Radar Family integrated in SiGe:C  

Microsoft Academic Search

Random noise radar attracts interest mainly because of its low interference and its camouflaged operation, as well as the relaxed requirements concerning transmitter power. Its challenge for very wideband operation is the impulse compression in order to gain range resolution. The use of pseudo random codes largely defuses this problem while keeping most advantages of random noise radar. Modern semi-conductor

J. Sachs; M. Kmec; R. Herrmann; P. Peyerl; P. Rauschenbach

2006-01-01

453

Ultra-Wideband UHF Microstrip Array for GeoSAR Application  

NASA Technical Reports Server (NTRS)

GeoSAR is a program sponsored by DARPA (Defense Advanced Research Projects Agency) and NASA (National Aeronautics and Space Administration) to develop an airborne, radar- based, commercial terrain mapping system for identification of geologic, seismic, and environmental information, it has two (dual-band at X and UHF) state-of-the-art interferometric synthetic aperture radar (SAR) ground mapping systems. The UHF interferometric system is utilized to penetrate the vegetation canopy and obtain true ground surface height information, while the Xband system will provide capability of mapping the top foliage surface. This paper presents the UHF antenna system where the required center frequency is 350 MHz with a 160 MHz of bandwidth (46% from 270 MHz to 430 MHz). The antenna is required to have dual-linear polarization with a peak gain of 10 dB at the center frequency and a minimum gain of 8 dB toward two ends of the frequency band. One of the most challenging tasks, in addition to achieving the 46% bandwidth, is to develop an antenna with small enough size to fit in the wing-tip pod of a Gulfstream II aircraft.

Thomas, Robert F.; Huang, John

1998-01-01

454

All-weather perception for man-portable robots using ultra-wideband radar  

Microsoft Academic Search

Autonomous man-portable robots have the potential to provide a wide range of new capabilities for both military and civilian applications. Previous research in autonomy for small robots has focused on vision, LIDAR, and sonar sensors. While vision and LIDAR work well in clear weather, they are seriously impaired by rain, snow, fog, and smoke. Sonar can penetrate adverse weather, but

Brian Yamauchi

2010-01-01

455

Design of Ultra wideband Microwave Antenna Array for Detection of Breast Cancer Tumours  

Microsoft Academic Search

The capabilities of current medical devices to detect breast cancer are agreeably insufficient for society’s needs. As such it is desirable for a new more reliable detection system to be fabricated. It has been reported in literature that cancerous tissue in the breast exhibits separate dielectric properties when compared to normal breast tissue at microwave frequencies. This report overviews the

Alistair Johnson

2009-01-01

456

Miniaturized Broadband Antenna Combining Fractal Patterns and Self-Complementary Structures for UWB Applications  

NASA Astrophysics Data System (ADS)

Miniaturized broadband antennas combining a fractal pattern and a self-complementary structure are demonstrated for UWB applications. Using four kinds of fractal patterns generated with an octagon initiator, similar to a self-complementary structure, we investigate the effect of the fractal pattern on broadband performance. The lower band-edge frequency of the broad bandwidth is decreased by the reduced constant input impedance, which is controlled by the vacant area size inside the fractal pattern. The reduced constant input impedance is shown to be produced by the extended current distribution flowing along the vacant areas. Given the results, miniaturized broadband antennas, impedance-matched to 50?, are designed and fabricated. The measured return loss was better than 10dB between 2.95 and 10.7GHz with a size of 27×12.5mm. The lower band-edge frequency was reduced by 28% compared with the initiator.

Dimitrov, Vasil; Saitou, Akira; Honjo, Kazuhiko

457

A Compact 5.5 GHz Band-Rejected UWB Antenna Using Complementary Split Ring Resonators  

PubMed Central

A band-removal property employing microwave frequencies using complementary split ring resonators (CSRRs) is applied to design a compact UWB antenna wishing for the rejection of some frequency band, which is meanwhile exercised by the existing wireless applications. The reported antenna comprises optimization of a circular radiating patch, in which slotted complementary SRRs are implanted. It is printed on low dielectric FR4 substrate material fed by a partial ground plane and a microstrip line. Validated results exhibit that the reported antenna shows a wide bandwidth covering from 3.45 to more than 12?GHz, with a compact dimension of 22 × 26?mm2, and VSWR < 2, observing band elimination of 5.5?GHz WLAN band.

Islam, M. M.; Faruque, M. R. I.; Islam, M. T.

2014-01-01

458

A Compact 5.5 GHz Band-Rejected UWB Antenna Using Complementary Split Ring Resonators.  

PubMed

A band-removal property employing microwave frequencies using complementary split ring resonators (CSRRs) is applied to design a compact UWB antenna wishing for the rejection of some frequency band, which is meanwhile exercised by the existing wireless applications. The reported antenna comprises optimization of a circular radiating patch, in which slotted complementary SRRs are implanted. It is printed on low dielectric FR4 substrate material fed by a partial ground plane and a microstrip line. Validated results exhibit that the reported antenna shows a wide bandwidth covering from 3.45 to more than 12?GHz, with a compact dimension of 22 × 26?mm(2), and VSWR < 2, observing band elimination of 5.5?GHz WLAN band. PMID:24971379

Islam, M M; Faruque, M R I; Islam, M T

2014-01-01

459

Applications of Short-Range Wireless Technologies to Industrial Automation: A ZigBee Approach  

Microsoft Academic Search

Bluetooth, ultra-wideband (UWB), ZigBee, and Wi-Fi are four popular wireless standards for short-range communications. Specifically, ZigBee network is an emerging technology designed for low cost, low power consumption and low-rate wireless personal area networks (LR-WPAN) with a focus on the device-level communication for enabling the wireless sensor networks. In this paper, after a brief overview of the four short-range wireless

Jin-shyan Lee; Chun-chieh Chuang; Chung-chou Shen

2009-01-01

460

A 3.1–10.6 GHz ultra-wide band CMOS low noise amplifier with band rejection  

Microsoft Academic Search

tw Abstract - This paper presents an ultra wideband (UWB) low noise amplifier (LNA) with band rejection which is implemented with T8MC 0.18-Jlm CM08 process. In the proposed chip, a shunt peaking technique is used to have a considerably gain flatness; and that a notch filter with negative resistance is adopted with band rejection between 4.7-6.3 GHz. Besides, the power

Guo-Ming Sung; Chiu-Lung Shen

2011-01-01

461

ESD protection design for fully integrated CMOS RF power amplifiers with waffle-structured SCR  

Microsoft Academic Search

Waffle-structured SCR (silicon-controlled rectifier) has been studied as an effective on-chip ESD (electrostatic discharge) protection device for CMOS RF (radio-frequency) circuits. In this work, a novel on-chip ESD protection strategy using the waffle-structured SCR is proposed and co-designed with a CMOS UWB (ultra-wideband) PA (power amplifier). Before ESD stress, the RF performances of the ESD-protected PA have been demonstrated to

Ming-dou Ker; Chun-yu Lin; Guo-xuan Meng

2008-01-01

462

A Koch-Like Sided Fractal Bow-Tie Dipole Antenna  

Microsoft Academic Search

A novel Koch-like fractal curve is proposed to transform ultra-wideband (UWB) bow-tie into so called Koch-like sided fractal bow-tie dipole. A small isosceles triangle is cut off from center of each side of the initial isosceles triangle, then the procedure iterates along the sides like Koch curve does, forming the Koch-like fractal bow-tie geometry. The fractal bow-tie of each iterative

Daotie Li; Jun-fa Mao

2012-01-01

463

All-weather perception for small autonomous UGVs  

Microsoft Academic Search

For the TARDEC-funded Daredevil Project, iRobot Corporation is developing capabilities that will allow small UGVs to navigate autonomously in adverse weather and in foliage. Our system will fuse sensor data from ultra wideband (UWB) radar, LIDAR, stereo vision, GPS, and INS to build maps of the environment showing which areas are passable (e.g. covered by tall grass) and which areas

Brian Yamauchi

2008-01-01

464

Future wireless tutorial  

Microsoft Academic Search

Future wireless systems must find ways to make use of the increase of availability of spectrum for wireless applications that can co-exist with higher-priority users. Such techniques include: (1) Ultra Wideband (UWB) which attempts to share the spectrum by transmitting at very low power so as not to interfere with narrow-band transmissions, (2) Cognitive Radios that use spectrum sampling techniques

Michael A. Soderstrand

2010-01-01

465

Wireless Sensor Networks for Resources Tracking at Building Construction Sites  

Microsoft Academic Search

We evaluate the technical feasibility of applying emerging wireless network technologies for resources tracking at building construction sites. We first identify practical constraints in solving resource-tracking problems in an enclosed or partially covered environment. We then compare pros and cons of available localization principles and examine the latest wireless communication technologies, including Wi-Fi, Bluetooth, Ultra-Wideband (UWB) and ZigBee. We find

Xuesong Shen; Wu Chen; Ming Lu

2008-01-01

466

Moderately rough surface underground imaging via short-pulse quasi-ray Gaussian beams  

Microsoft Academic Search

An adaptive framework is presented for ultra-wideband ground penetrating radar imaging of shallow-buried low-contrast dielectric objects in the presence of a moderately rough air-soil interface. The proposed approach works with sparse data and relies on recently developed Gabor-based narrow-waisted quasi-ray Gaussian beam algorithms as fast forward scattering predictive models. First, a nonlinear inverse scattering problem is solved to estimate the

Vincenzo Galdi; Haihua Feng; David A. Castañon; William Clem Karl; Leopold B. Felsen

2003-01-01

467

Wearable system-on-a-chip UWB radar for health care and its application to the safety improvement of emergency operators.  

PubMed

A new wearable system-on-a-chip UWB radar for health care systems is presented. The idea and its applications to the safety improvement of emergency operators are discussed. The system consists of a wearable wireless interface including a fully integrated UWB radar for the detection of the heart beat and breath rates, and a IEEE 802.15.4 ZigBee radio interface. The principle of operation of the UWB radar for the monitoring of the heart wall is explained hereinafter. The results obtained by the feasibility study regarding its implementation on a modern standard silicon technology (CMOS 90 nm) are reported, demonstrating (at simulation level) the effectiveness of such an approach and enabling the standard silicon technology for new generations of wireless sensors for heath care and safeguard wearable systems. PMID:18002540

Zito, Domenico; Pepe, Domenico; Neri, Bruno; De Rossi, Danilo; Lanatà, Antonio; Tognetti, Alessandro; Scilingo, Enzo Pasquale

2007-01-01

468

SEMICONDUCTOR INTEGRATED CIRCUITS: A low-spurious fast-hopping MB-OFDM UWB synthesizer  

NASA Astrophysics Data System (ADS)

A frequency synthesizer for the ultra-wide band (UWB) group #1 is proposed. The synthesizer uses a phase-locked loop (PLL) and single-sideband (SSB) mixers to generate the three center frequencies of the first band group by mixing 4224 MHz with ±264 MHz and 792 MHz, respectively. A novel multi-QSSB mixer is designed to combine the function of frequency selection and frequency conversion for low power and high linearity. The synthesizer is fabricated in Jazz 0.18-?m RF CMOS technology. The measured reference spur is as low as -69 dBc and the maximum spur is the LO leakage of -32 dBc. A low phase noise of -110 dBc/Hz @ 1 MHz offset and an integrated phase noise of 1.86° are achieved. The hopping time between different bands is less than 1.8 ns. The synthesizer consumes 30 mA from a 1.8 V supply.

Danfeng, Chen; Wei, Li; Ning, Li; Junyan, Ren

2010-06-01

469

Efficient Management of Multiple Piconets in an MC-CDMA-Based UWB System  

NASA Astrophysics Data System (ADS)

With multiple overlapped piconets, the IEEE 802.15.3 Medium Access Control (MAC) protocol uses a Parent/Child (P/C) or Parent/Neighbor (P/N) configuration to avoid inter-piconet interference. However, the throughput of a P/N or P/C configuration cannot exceed that of a single piconet. In the present paper we propose an efficient means of managing multiple piconets to cooperate with a Multi-Carrier Code Division Multiple Access (MC-CDMA) based UWB system. The proposed management approach uses an Intermediate Device (IDEV) to connect Piconet Coordinators (PNCs). A senior PNC adaptively arranges two simultaneous data transmission links with the proposed spreading matrices in each Channel Time Allocation (CTA) instead of a P/C or P/N configuration, which supports only a single link in each CTA. Simulation results demonstrate the proposed scheme can achieve a higher throughput with an acceptable compromise of link success probability in multiple overlapped piconets.

Gong, Peng; Xue, Peng; Piao, Cheng Jie; Kim, Duk Kyung

470

A monolithic 3.1–4.8 GHz MB-OFDM UWB transceiver in 0.18-?m CMOS  

Microsoft Academic Search

A monolithic RF transceiver for an MB-OFDM UWB system in 3.1–4.8 GHz is presented. The transceiver adopts direct-conversion architecture and integrates all building blocks including a gain controllable wideband LNA, a I\\/Q merged quadrature mixer, a fifth-order Gm–C bi-quad Chebyshev LPF\\/VGA, a fast-settling frequency synthesizer with a poly-phase filter, a linear broadband up-conversion quadrature modulator, an active D2S converter and

Zheng Renliang; Jiang Xudong; Yao Wang; Yang Guang; Yin Jiangwei; Zheng Jianqin; Ren Junyan; Li Wei; Li Ning

2010-01-01

471

Ultra Wide Band (UWB) Radar Detection Analysis and Demonstration Program, Phases 1 and 2. Volume 1.  

National Technical Information Service (NTIS)

This report presents the T-pulse concept. The first part presents the T-pulse as a flexible tool for the analysis of waveforms exhibiting time-frequency localization. This is useful when T-pulse processing is performed on receive. It is shown how the T-pu...

D. D. Weiner H. Wang T. K. Sarkar

1995-01-01

472

Design and Performance Evaluation of a UWB Communication and Tracking System for Mini-AERCam  

NASA Technical Reports Server (NTRS)

NASA Johnson Space Center (JSC) is developing a low-volume, low-mass, robotic free-flying camera known as Mini-AERCam (Autonomous Extra-vehicular Robotic Camera) to assist the International Space Station (ISS) operations. Mini-AERCam is designed to provide astronauts and ground control real-time video for camera views of ISS. The system will assist ISS crewmembers and ground personnel to monitor ongoing operations and perform visual inspections of exterior ISS components without requiring extravehicular activity (EAV). Mini-AERCam consists of a great number of subsystems. Many institutions and companies have been involved in the R&D for this project. A Mini-AERCam ground control system has been studied at Texas A&M University [3]. The path planning and control algorithms that direct the motions of Mini-AERCam have been developed through the joint effort of Carnegie Mellon University and the Texas Robotics and Automation Center [5]. NASA JSC has designed a layered control architecture that integrates all functions of Mini-AERCam [8]. The research described in this report is part of a larger effort focused on the communication and tracking subsystem that is designed to perform three major tasks: 1. To transmit commands from ISS to Mini-AERCam for control of robotic camera motions (downlink); 2. To transmit real-time video from Mini-AERCam to ISS for inspections (uplink); 3. To track the position of Mini-AERCam for precise motion control. The ISS propagation environment is unique due to the nature of the ISS structure and multiple RF interference sources [9]. The ISS is composed of various truss segments, solar panels, thermal radiator panels, and modules for laboratories and crew accommodations. A tracking system supplemental to GPS is desirable both to improve accuracy and to eliminate the structural blockage due to the close proximity of the ISS which could at times limit the number of GPS satellites accessible to the Mini-AERCam. Ideally, the tracking system will be a passive component of the communication system which will need to operate in a time-varying multipath environment created as the robot camera moves over the ISS structure. In addition, due to many interference sources located on the ISS, SSO, LEO satellites and ground-based transmitters, selecting a frequency for the ISS and Mini-AERCam link which will coexist with all interferers poses a major design challenge. To meet all of these challenges, ultrawideband (UWB) radio technology is being studied for use in the Mini-AERCam communication and tracking subsystem. The research described in this report is focused on design and evaluation of passive tracking system algorithms based on UWB radio transmissions from mini-AERCam.

Barton, Richard J.

2005-01-01

473

Multi-wavelength, 4.32 Gbps UWB radio-over-fiber demonstration featuring a reflective electro-absorption transceiver and low-Cost DWDM grid VCSELs  

Microsoft Academic Search

We demonstrate multi-wavelength UWB radio-over-fiber transmission with 4.32 Gbps throughput over 26.2 km of fiber using a reflective electro-absorption transceiver. Overall EVMs better than -16.8 dB were measured for three VCSEL wavelengths from 1536.3 nm to 1537.8 nm.

Manoj P. Thakur; Terence Quinlan; S. B. Ahmad Anas; D. K. Hunter; S. D. Walker; D. W. Smith; A. Borghesani; D. Moodie

2009-01-01

474

A Framework for Computing Detection and False Alarm Probabilities for IR-UWB Transmitted Reference Receivers over Generalized Fading Channels with Tone Interference  

Microsoft Academic Search

In this paper, we propose an analytical framework for computing Detection (PD) and False Alarm (P FA ) Probabili- ties for Impulse Radio Ultra Wide Band (IR-UWB) Transmitted- Reference (TR) receivers in a quite general scenario, which includes generalized multipath fading channels and narrow- band interference as well. The proposed framework is intended to overcome the limitations of current frameworks

Marco Di Renzo; Fabio Graziosi; Fortunato Santucci

2008-01-01

475

Advanced signal processing method for ground penetrating radar feature detection and enhancement  

NASA Astrophysics Data System (ADS)

This paper focuses on new signal processing algorithms customized for an air coupled Ultra-Wideband (UWB) Ground Penetrating Radar (GPR) system targeting highway pavements and bridge deck inspections. The GPR hardware consists of a high-voltage pulse generator, a high speed 8 GSps real time data acquisition unit, and a customized field-programmable gate array (FPGA) control element. In comparison to most existing GPR system with low survey speeds, this system can survey at normal highway speed (60 mph) with a high horizontal resolution of up to 10 scans per centimeter. Due to the complexity and uncertainty of subsurface media, the GPR signal processing is important but challenging. In this GPR system, an adaptive GPR signal processing algorithm using Curvelet Transform, 2D high pass filtering and exponential scaling is proposed to alleviate noise and clutter while the subsurface features are preserved and enhanced. First, Curvelet Transform is used to remove the environmental and systematic noises while maintain the range resolution of the B-Scan image. Then, mathematical models for cylinder-shaped object and clutter are built. A two-dimension (2D) filter based on these models removes clutter and enhances the hyperbola feature in a B-Scan image. Finally, an exponential scaling method is applied to compensate the signal attenuation in subsurface materials and to improve the desired signal feature. For performance test and validation, rebar detection experiments and subsurface feature inspection in laboratory and field configurations are performed.

Zhang, Yu; Venkatachalam, Anbu Selvam; Huston, Dryver; Xia, Tian

2014-03-01

476

Pulse transformers  

Microsoft Academic Search

Pulse transformers capable of transmitting substantially rectangular voltage pulses, with durations of less than one microsecond, were developed for radar applications during World War II. Their primary functions were to match the impedances of high-power microwave radio-frequency electron-tube generators to electronic pulse generators and coaxial transmission cables, and to provide polarity reversal and impedance matching functions within pulse generator circuitry.

H. Lord

1971-01-01

477

Time-domain calculation of sub-nanosecond pulse launched by a proton beam  

SciTech Connect

Using the finite-difference time-domain code TBCI, we have numerically calculated the radiation from a sub-nanosecond 800-MeV proton bunch as it is launched into space. The calculation is compared to measurements of the time history of the radiated fields and good agreement is found. A movie showing the development of the radiation pattern will be shown during the presentation at this conference, namely, the First Los Alamos Symposium on Ultra-Wideband Radar. 6 refs., 7 figs.

Chan, Kwok-Chi Dominic; Cooper, R.K.

1990-01-01

478

PLL Architecture for 77GHz FMCW Radar Systems with Highly-Linear Ultra-Wideband Frequency Sweeps  

Microsoft Academic Search

The successful implementation of a linear frequency modulated continuous wave (FMCW) radar transmitter is presented, consisting of a 77-GHz voltage controlled oscillator (VCO) and a 19-GHz down-converter manufactured in a 200-GHz silicon germanium (SiGe) technology. The influence of phase noise and frequency sweep linearity on the radar system performance is briefly described, and measurement results of these parameters are compared

Christoph Wagner; Andreas Stelzer; H. Jager

2006-01-01

479

Near Surface Accumulation Patterns in the Recovery Lakes Area as Revealed by AN Ultra-Wideband Ground Based Radar  

NASA Astrophysics Data System (ADS)

High-frequency radar data were collected on the second leg of the Norwegian-US traverse from South Pole to Troll Station in 2008/09. The traverse route went directly over all four Recovery Lakes, which have been identified previously from remote sensing data. We used a ground-based high-frequency FMCW radar with a center frequency of 1.75 GHz. The radar data covering the uppermost 100 m of the firn pack are used to examine subsurface structures at the proposed lake margins. We combine radar and dated firn core data to determine local accumulation anomalies and areas of different flow velocities.

Sinisalo, A. K.; Müller, K.; Langley, K.; Anschütz, H.; Hamran, S.; Øyan, M.; Hagen, J. M.; Kohler, J.; Melland, G.; McConnell, J. R.

2010-12-01

480

Broadband (Ultra Wideband) Sensor System and Signal Processing Techniques for Active and Passive Detection and Classification of Targets.  

National Technical Information Service (NTIS)

This report discusses a Broadband Bionic Sonar System and a signal processing technique for detection and identification of underwater targets. Since the sonar and radar target echoes are the solutions to the same Helmholtz Equation in their respective me...

G. Goo

1999-01-01

481

Diversity-Multiplexing Tradeoff of Single-Antenna and Multi-Antenna Indoor Ultra-Wideband Channels  

Microsoft Academic Search

In this paper, we study the achievable diversity-multiplexing gain (D-MG) tradeoffs over the IEEE 802.15.3a channel model. In particular, we give an exact expression of the D-MG tradeoff for single antenna systems. This expression is based on a statistical model of the integrated energy of the considered channels. At a second time, we evaluate lower and upper bounds on the

C. Abou-Rjeily; N. Daniele; J.-C. Belfiore

2006-01-01

482

Tunable ultra-wideband terahertz filter based on three-dimensional arrays of H-shaped plasmonic crystals  

NASA Astrophysics Data System (ADS)

A face-to-face system of double-layer three-dimensional arrays of H-shaped plasmonic crystals is proposed, and its transmission and filtering properties are investigated in the terahertz regime. Simulation results show that our design has excellent filtering properties. It has an ultra-wide bandgap and passband with steep band-edges, and the transmittance of the passband and the forbidden band are very close to 1 and 0, respectively. As the distance between the two face-to-face plates increases, the resonance frequency exhibits a gradual blueshift from 0.88 THz to 1.30 THz. Therefore, we can dynamically control the bandwidths of bandgap and passband by adding a piezoelectric ceramic plate between the two crystal plates. Furthermore, the dispersion relations of modes and electric field distributions are presented to analyze the generation mechanisms of bandgaps and to explain the location of bandgaps and the frequency shift phenomenon. Due to the fact that our design can provide many resonant modes, the bandwidth of the bandgaps can be greatly broadened. This paper can serve as a valuable reference for the design of terahertz functional devices and three-dimensional terahertz metamaterials.

Yuan, Cai; Xu, Shi-Lin; Yao, Jian-Quan; Zhao, Xiao-Lei; Cao, Xiao-Long; Wu, Liang

2014-01-01

483

Design and optimization of an ultra wideband and compact microwave antenna for radiometric monitoring of brain temperature.  

PubMed

We present the modeling efforts on antenna design and frequency selection to monitor brain temperature during prolonged surgery using noninvasive microwave radiometry. A tapered log-spiral antenna design is chosen for its wideband characteristics that allow higher power collection from deep brain. Parametric analysis with the software HFSS is used to optimize antenna performance for deep brain temperature sensing. Radiometric antenna efficiency (?) is evaluated in terms of the ratio of power collected from brain to total power received by the antenna. Anatomical information extracted from several adult computed tomography scans is used to establish design parameters for constructing an accurate layered 3-D tissue phantom. This head phantom includes separate brain and scalp regions, with tissue equivalent liquids circulating at independent temperatures on either side of an intact skull. The optimized frequency band is 1.1-1.6 GHz producing an average antenna efficiency of 50.3% from a two turn log-spiral antenna. The entire sensor package is contained in a lightweight and low-profile 2.8 cm diameter by 1.5 cm high assembly that can be held in place over the skin with an electromagnetic interference shielding adhesive patch. The calculated radiometric equivalent brain temperature tracks within 0.4 °C of the measured brain phantom temperature when the brain phantom is lowered 10 °C and then returned to the original temperature (37 °C) over a 4.6-h experiment. The numerical and experimental results demonstrate that the optimized 2.5-cm log-spiral antenna is well suited for the noninvasive radiometric sensing of deep brain temperature. PMID:24759979

Rodrigues, Dario B; Maccarini, Paolo F; Salahi, Sara; Oliveira, Tiago R; Pereira, Pedro J S; Limao-Vieira, Paulo; Snow, Brent W; Reudink, Doug; Stauffer, Paul R

2014-07-01

484

A comparison of time versus frequency domain antenna patterns  

Microsoft Academic Search

This paper compares the performance of antenna arrays that use sinusoidal and ultra-short pulse waveforms. There are two parts to the paper: first, a comparison of narrowband versus ultra-wideband linear arrays using an analytic approach and second, a series of computer simulations used to extend the analytic results and to show the characteristics of nonstandard array configurations. Analysis shows that

Leo D. DiDomenico

2002-01-01

485

Confocal microwave imaging for breast cancer detection: localization of tumors in three dimensions  

Microsoft Academic Search

The physical basis for breast tumor detection with microwave imaging is the contrast in dielectric properties of normal and malignant breast tissues. Confocal microwave imaging involves illuminating the breast with an ultra-wideband pulse from a number of antenna locations, then synthetically focusing reflections from the breast. The detection of malignant tumors is achieved by the coherent addition of returns from

Elise C. Fear; X. Li; S. C. Hagness; M. A. Stuchly

2002-01-01

486

Multigigahertz beam diagnostics for laser fusion  

SciTech Connect

A system to make ultra wideband measurements of fast laser pulses and their induced target interactions at a distance of approximately 38 m from the target location is discussed. The system has demonstrated an overall bandwidth of 3 GHz with projected unfolding to 4 GHz. This system allows high resolution temporal history diagnostics in a remote location providing high EMI and radiation immunity.

Smith, R.C.; Hodson, E.K.; Carlson, R.L.

1981-01-01

487

Pulse Data.  

ERIC Educational Resources Information Center

Presents an activity using computer software to investigate the role of the heart and blood, how the blood system responds to exercise, and how pulse rate is a good measure of physical condition. (ASK)

Hands On!, 1998

1998-01-01

488

Pulse stretcher  

DOEpatents

Apparatus (20) for increasing the length of a laser pulse to reduce its peak power without substantial loss in the average power of the pulse. The apparatus (20) uses a White cell (10) having a plurality of optical delay paths (18a-18d) of successively increasing number of passes between the field mirror (13) and the objective mirrors (11 and 12). A pulse (26) from a laser (27) travels through a multi-leg reflective path (28) between a beam splitter (21) and a totally reflective mirror (24) to the laser output (37). The laser pulse (26) is also simultaneously injected through the beam splitter (21) to the input mirrors (14a-14d) of the optical delay paths (18a-18d). The pulses from the output mirrors (16a-16d) of the optical delay paths (18a-18d) go simultaneously to the laser output (37) and to the input mirrors ( 14b-14d) of the longer optical delay paths. The beam splitter (21) is 50% reflective and 50% transmissive to provide equal attenuation of all of the pulses at the laser output (37).

Horton, James A. (Livermore, CA) [Livermore, CA

1994-01-01

489

A Wide Range CMOS Power Amplifier with Improved Group Delay Variation and Gain Flatness for UWB Transmitters  

NASA Astrophysics Data System (ADS)

This paper presents the design and implementation of 0.9-4.8GHz CMOS power amplifier (PA) with improved group delay variation and gain flatness at the same time for UWB transmitters. This PA design employs a two-stage cascade common source topology, a resistive shunt feedback technique and inductive peaking to achieve high gain flatness, and good input matching. Based on theoretical analysis, the main design factor for group delay variation is identified. The measurement results indicate that the proposed PA design has an average gain of 10.2 ± 0.8dB while maintaining a 3-dB bandwidth of 0.57 to 5.8GHz, an input return loss |S11| less than -4.4dB, and an output return loss |S22| less than -9.2dB over the frequency range of interest. The input 1dB compression point at 2GHz was -9dBm while consumes 30mW power from 1.5V supply voltage. Moreover, excellent phase linearity (i.e., group delay variation) of ±125ps was achieved across the whole band.

Sapawi, Rohana; K. Pokharel, Ramesh; Kanaya, Haruichi; Yoshida, Keiji

490

SEMICONDUCTOR INTEGRATED CIRCUITS: A 4 GHz quadrature output fractional-N frequency synthesizer for an IR-UWB transceiver  

NASA Astrophysics Data System (ADS)

This paper describes a 4 GHz fractional-N frequency synthesizer for a 3.1 to 5 GHz IR-UWB transceiver. Designed in a 0.18 ?m mixed-signal & RF 1P6M CMOS process, the operating range of the synthesizer is 3.74 to 4.44 GHz. By using an 18-bit third-order ?-? modulator, the synthesizer achieves a frequency resolution of 15 Hz when the reference frequency is 20 MHz. The measured amplitude mismatch and phase error between I and Q signals are less than 0.1 dB and 0.8o respectively. The measured phase noise is -116 dBc/Hz at 3 MHz offset for a 4 GHz output. Measured spurious tones are lower than -60 dBc. The settling time is within 80 ?s. The core circuit conupSigmaes only 38.2 mW from a 1.8 V power supply.

Shita, Guo; Lu, Huang; Haiquan, Yuan; Lisong, Feng; Zhiming, Liu

2010-03-01

491

SEMICONDUCTOR INTEGRATED CIRCUITS: A monolithic 3.1-4.8 GHz MB-OFDM UWB transceiver in 0.18-mum CMOS  

Microsoft Academic Search

A monolithic RF transceiver for an MB-OFDM UWB system in 3.1-4.8 GHz is presented. The transceiver adopts direct-conversion architecture and integrates all building blocks including a gain controllable wideband LNA, a I\\/Q merged quadrature mixer, a fifth-order Gm-C bi-quad Chebyshev LPF\\/VGA, a fast-settling frequency synthesizer with a poly-phase filter, a linear broadband up-conversion quadrature modulator, an active D2S converter and

Zheng Renliang; Jiang Xudong; Yao Wang; Yang Guang; Yin Jiangwei; Zheng Jianqin; Ren Junyan; Li Wei; Li Ning

2010-01-01

492

Pulse Oximetry  

MedlinePLUS

... you are exercising or if you travel to high altitude. Having a pulse oximeter in these cases will allow you to monitor your blood oxygen level and know when you need to increase your supplemental oxygen flow rate. Ask your health care provider what oxygen ...

493

Pulsed hydrojet  

DOEpatents

An underwater pulsed hydrojet propulsion system is provided for accelerating and propelling a projectile or other vessel. A reactant, such as lithium, is fluidized and injected into a water volume. The resulting reaction produces an energy density in a time effective to form a steam pocket. Thrust flaps or baffles direct the pressure from the steam pocket toward an exit nozzle for accelerating a water volume to create thrust. A control system regulates the dispersion of reactant to control thrust characteristics.

Bohachevsky, I.O.; Torrey, M.D.

1986-06-10

494

Digital Pulse  

NSDL National Science Digital Library

When high technology crashes into popular culture you've got Digital Pulse, the heartbeat of the infotainment infobahn with exclusive news and tips from the experts at CMP's Windows Magazine, NetGuide, Home PC and more. This week read about Adam Curry's deal with BMI which will let him sell (and us buy) digital recordings over the 'Net. Free registration is required on Pathfinder, Time Warner's home on the internet.

495

Tapered pulse tube for pulse tube refrigerators  

DOEpatents

Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.

Swift, Gregory W. (Sante Fe, NM); Olson, Jeffrey R. (San Mateo, CA)

1999-01-01

496

SEMICONDUCTOR INTEGRATED CIRCUITS: A 3-5 GHz BPSK transmitter for IR-UWB in 0.18 ?m CMOS  

NASA Astrophysics Data System (ADS)

This paper presents a transmitter IC with BPSK modulation for an ultra-wide band system. It is based on up-conversion with a high linearity passive mixer. Unlike the traditional BPSK modulation scheme, the local oscillator (LO) is modulated by the baseband data instead of the pulse. The chip is designed and fabricated by standard 0.18 ?m CMOS technology. The transmitter achieves a high data rate up to 400 Mbps. The amplitude of the pulse can be adjusted by the amplitude of the LO and the bias current of the driver amplifier. The maximum peak-to-peak amplitude of the pulse is 600 mV. It consumes only 20.3 mA current with a supply voltage of 1.8 V when transmitting a pulse at the maximum data rate. The energy efficiency is 91.4 pJ/pulse. The die area is 1.4 × 1.4 mm2.

Delong, Fu; Lu, Huang; Li, Cai; Fujiang, Lin

2010-09-01

497

Nanosecond, kilovolt pulse generators  

Microsoft Academic Search

Nanosecond pulse generators, which provide kilovolt pulses, are required for applications such as pulsed lasers, electro-optical devices, electron heating of plasmas, and bioelectrics. Switches used to generate such short pulses include high-pressure spark gaps, photoconductive switches and semiconductor opening switches. Most of the pulse generators based on these switch technologies are designed for high voltage, high power applications. We have

U. Hahn; M. Herrmann; F. Leipold; K. H. Schoenbach

2001-01-01

498

480 Mbit/s UWB bi-directional radio over fiber CWDM PON using ultra-low cost and power VCSELs.  

PubMed

Radio-over-fiber (RoF) schemes offer the possibility of permitting direct access to native format services for the domestic user. A low power requirement and cost effectiveness are crucial to both the service provider and the end user. Here, we present an ultra-low cost and power RoF scheme using direct modulation of commercially-available 1344 nm and 1547 nm VCSELs by band-group 1 UWB wireless signals (ECMA-368) at near broadcast power levels. As a result, greatly simplified electrical-optical-electrical conversion is accomplished. A successful demonstration over a transmission distance of 20.1 km is described using a SSMF, CWDM optical network. EVMs of better than -18.3 dB were achieved. PMID:22274019

Quinlan, Terence; Morant, Maria; Dudley, Sandra; Llorente, Roberto; Walker, Stuart

2011-12-12

499

SEMICONDUCTOR INTEGRATED CIRCUITS: A 1.5 V 7.656 GHz PLL with I/Q outputs for a UWB synthesizer  

NASA Astrophysics Data System (ADS)

A fully integrated CMOS phase-locked loop (PLL) which can synthesize a quadrature output frequency of 7.656 GHz is presented. The proposed PLL can be employed as a building block for an MB-OFDM UWB frequency synthesizer. To achieve fast loop settling, integer- N architecture operating with 66 MHz reference frequency and wideband QVCO are implemented. I/Q carriers are generated by two bottom-series cross-coupled LC VCOs. Realized in 0.18 ?m CMOS technology, this PLL consumes 16 mA current (including buffers) from a 1.5 V supply and the phase noise is -109.6 dBc/Hz at 1 MHz offset. The measured oscillation frequency shows that the QVCO has a range of 6.95 to 8.73 GHz. The core circuit occupies an area of 1 × 0.5 mm2.

Pufeng, Chen; Haiying, Zhang; Tianchun, Ye

2010-06-01

500

Emerging Communication Technologies (ECT) Phase 2 Report. Volume 1; Main Report  

NASA Technical Reports Server (NTRS)

The Emerging Communication Technology (ECT) project investigated three First Mile communication technologies in support of NASA s Second Generation Reusable Launch Vehicle (2nd Gen RLV), Orbital Space Plane, Advanced Range Technology Working Group (ARTWG) and the Advanced Spaceport Technology Working Group (ASTWG). These First Mile technologies have the purpose of interconnecting mobile users with existing Range Communication infrastructures. ECT was a continuation of the Range Information System Management (RISM) task started in 2002. RISM identified the three advance communication technologies investigated under ECT. These were Wireless Ethernet (Wi-Fi), Free Space Optics (FSO), and Ultra Wideband (UWB). Due to the report s size, it has been broken into three volumes: 1) Main Report 2) Appendices 3) UWB.

Bastin, Gary L.; Harris, William G.; Chiodini, Robert; Nelson, Richard A.; Huang, PoTien; Kruhm, David A.

2003-01-01