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1

An N-Bit Digitally Variable Ultra Wideband Pulse Generator for GPR and UWB Applications  

E-print Network

has found military applications such as ground penetrating radar (GPR), wall penetrating radar, secure. Particularly, in UWB ground penetrating radar, a digitally tunable pulse generator allows the pulse width on the resolution of the radar. If the impulse radio is used as GPR to provide high penetration depth, higher pulse

Yanikoglu, Berrin

2

High-rate transmission scheme for pulse-based ultra-wideband systems over dense multipath  

E-print Network

High-rate transmission scheme for pulse-based ultra-wideband systems over dense multipath indoor-forcing (ZF), and a high-performance ZF-based successive receiver for effective detection in the presence-based ultra-wideband (UWB) systems [1­10] transmits one short- duration, low-duty-cycle pulse every pulse

Liu, Huaping

3

Pulse-based ultra-wideband transmitters for digital communication  

E-print Network

Ultra-wideband radio (UWB) is a rapidly developing wireless technology that promises unprecedented data rates for short-range commercial radios, combined with precise locationing and high energy efficiency. These benefits ...

Wentzloff, David D. (David Dale), 1977-

2007-01-01

4

A new ultra-wideband, ultra-short monocycle pulse generator with reduced ringing  

Microsoft Academic Search

We introduce a new ultra-wideband (UWB), ultra-short, step recovery diode monocycle pulse generator. This pulse generator uses a simple RC high-pass filter as a differentiator to generate the monocycle pulse directly. The pulse-shaping network employs a resistive circuit to achieve UWB matching and substantial removal of the pulse ringing, and rectifying and switching diodes to further suppress the ringing. An

Jeongwoo Han; Cam Nguyen

2002-01-01

5

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

6

An ultra-wideband CMOS low noise amplifier for 3-5GHz UWB system  

Microsoft Academic Search

Abstract—An ultra-wideband (UWB) CMOS low noise amplifier (LNA) topology that combines a narrowband LNA with a resistive shunt-feedback is proposed. The resistive shunt-feedback provides wideband input matching with small noise figure (NF) degradation by reducing the Q-factor of the narrowband LNA input and flattens the passband gain. The proposed UWB amplifier is implemented in 0.18- m CMOS technology for a

Chang-Wan Kim; Min-Suk Kang; Phan Tuan Anh; Hoon-Tae Kim; Sang-Gug Lee

2005-01-01

7

Accuracy of Free Space Path Loss and Matched Filter Gain Approximated by Using Passband Rectangular Pulse for Ultra Wideband Radio Systems  

Microsoft Academic Search

This paper analyzes the accuracy of free space path loss and matched filter gain approximated by using a passband rectangular pulse for ultra wideband (UWB) radio systems. The example causal signal, a modulated Gaussian pulse with the same center frequency and frequency bandwidth of the passband rectangular pulse, is used to consider the accuracy. The path loss and matched filter

Pichaya Supanakoon; Suchada Tanchotikul; Prakit Tangtisanon; Sathaporn Promwong; Jun-ichi Takada

2004-01-01

8

Characterization of inter-pulse interference and fading for ultra-wideband systems  

Microsoft Academic Search

A statistical characterization is presented of the im- pact of the ultra-wideband (UWB) multipath channel on impulse radio and spread-spectrum UWB systems. For this purpose, the correlator output statistics are studied, since correlators are the typical first processing step in the frontends of coherent and noncoherent receivers. The analysis is based on the second and forth-order moments of the channel

Klaus Witrisal; Marco Pausini

2011-01-01

9

Commercialization of an ultra wideband precision asset location system  

Microsoft Academic Search

Ultra wideband (UWB) technology has been shown to possess unique advantages for precision localization applications. The use of short pulse RF waveforms provides inherent precision for time difference of arrival measurements, as well immunity to multipath effects in indoor applications. This paper describes an FCC-approved, commercial UWB precision asset location system which is being used for tracking of high valued

Robert J. Fontana; Edward Richley; JoAnn Barney

2003-01-01

10

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

11

Pulsed frequency modulation techniques for high-precision ultra wideband ranging and positioning  

Microsoft Academic Search

In this paper a novel approach for a high precision local positioning radar using an ultra wideband technique is presented. The concept is based on the standard FMCW (frequency modulated continuous wave) radar principle combined with short pulses to fulfill the emission limits given by the official regulatory authorities. The system combines the advantages of FMCW radar systems and the

Benjamin Waldmann; Robert Weigel; Peter Gulden; Martin Vossiek

2008-01-01

12

A 0.17-nJ/Pulse IR-UWB Receiver Based on Distributed Pulse Correlator in 0.18-m Digital CMOS  

E-print Network

A 0.17-nJ/Pulse IR-UWB Receiver Based on Distributed Pulse Correlator in 0.18-µm Digital CMOS@ece.rochester.edu Abstract-- This paper presents a low power impulse-radio ultra-wideband (IR-UWB) receiver based and circuit complexity of the analog correlation receiver. A chip prototype of the IR-UWB receiver

Wu, Hui

13

Ultra wideband surface wave communications  

NASA Astrophysics Data System (ADS)

Ultra Wideband (UWB), an impulse carrier waveform, was applied at HF-VHF frequencies to utilize surface wave propagation. UWB involves the propagation of transient pulses rather than continuous waves which makes the system easier to implement, inexpensive, low power and small. Commercial UWB for wireless personal area networks is 3.1 to 10.6 GHz band as approved by the FCC with ranges up to 12 ft. The use of surface wave propagation (instead of commercial SHF UWB) extends the communication range. Surface wave is a means of propagation where the wave is guided by the surface of the Earth. Surface wave is efficient at low frequencies, VLF to HF. The UWB HF channel was modeled and also experimentally characterized. The Federal Communications Commission (FCC) defines UWB as a signal with either a fractional bandwidth of 20% of the center frequency or a bandwidth of 500MHz. Designing an antenna to operate over the 20% bandwidth requirement of UWB is one of the greatest challenges. Two different antenna designs are presented, a spoke top antenna and a traveling wave antenna with photonic bandgap. These designs were implemented at the commercial UWB frequencies (3.1--10.6 GHz) due to availability of modeling tools for the higher frequencies, the reduced antenna size and the availability of measurement facilities. The spoke top was optimum for replication of the time domain input signal. The traveling wave antenna with photonic bandgap demonstrated increased impedance bandwidth of the antenna.

Lacomb, Julie Anne

14

Through-the-Wall Localization of a Moving Target by Two Independent Ultra Wideband (UWB) Radar Systems  

PubMed Central

In the case of through-the-wall localization of moving targets by ultra wideband (UWB) radars, there are applications in which handheld sensors equipped only with one transmitting and two receiving antennas are applied. Sometimes, the radar using such a small antenna array is not able to localize the target with the required accuracy. With a view to improve through-the-wall target localization, cooperative positioning based on a fusion of data retrieved from two independent radar systems can be used. In this paper, the novel method of the cooperative localization referred to as joining intersections of the ellipses is introduced. This method is based on a geometrical interpretation of target localization where the target position is estimated using a properly created cluster of the ellipse intersections representing potential positions of the target. The performance of the proposed method is compared with the direct calculation method and two alternative methods of cooperative localization using data obtained by measurements with the M-sequence UWB radars. The direct calculation method is applied for the target localization by particular radar systems. As alternative methods of cooperative localization, the arithmetic average of the target coordinates estimated by two single independent UWB radars and the Taylor series method is considered. PMID:24021968

Kocur, Dušan; Švecová, Mária; Rov?áková, Jana

2013-01-01

15

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

16

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

17

RF CMOS UWB transmitter and receiver front-end design  

E-print Network

The low-cost low-power complementary metal-oxide semiconductor (CMOS) ultra wideband (UWB) transmitter and receiver front-ends based on impulse technology were developed. The CMOS UWB pulse generator with frequency-band tuning capability...

Miao, Meng

2009-05-15

18

A Low-Power CMOS Modulator for Ultra-Wideband Transmitters  

Microsoft Academic Search

A low-power CMOS modulator for carrier-based ultra-wideband (UWB) transmitters is presented. The core of the circuit consists of an oscillator and two control switches. The oscillator sets the center frequency of the UWB signal. The spectrum of the baseband data pulse is frequency translated to the desired band without using an explicit mixer. Since in many pulse-based UWB systems, in

Shahrzad Jalali Mazlouman; Alireza Mahanfar; Shahriar Mirabbasi

2007-01-01

19

RETRACTED — Photonic generation of UWB pulses with multiple modulation formats  

NASA Astrophysics Data System (ADS)

A new photonic approach to generate ultra-wideband (UWB) signals with on-off keying, pulse position and shape modulation is proposed and proved by simulation. The proposed system consists of two parallel similar subsystems, which are both made up of an intensity modulator (IM) and a dual-drive Mach-Zehnder modulator (DD-MZM). The optical signal is injected into the two subsystems with equal intensity and phase. The IMs are driven by the data signal, while the DD-MZMs are driven by the Gaussian pulse train. By properly adjusting the bias points of the IMs and DD-MZMs, the amplitudes of the data signals, and the time delays introduced by electrical delay lines, a position-modulated UWB monocycle, a shape-modulated UWB monocycle and doublet, and an on-off keying UWB monocycle can be generated. The fractional bandwidth of the generated UWB monocycle and UWB doublet are 171% and 150%, respectively.

Chen, Yang; Wen, Aijun; Shang, Lei; Wang, Yong

2013-02-01

20

Impact Of Ultra Wideband (Uwb) Radio Range On Wireless Sensor Networks  

E-print Network

ability, and low transmission power [1]-[4]. To operate in the harsh radio environment of a factory, an I and devices. Typical narrowband radios may be forced to increase their radiated power to maintain network radios in a sensor network. However, the radiated power of I-UWB radios is severely limited

Ha, Dong S.

21

Ultra-wideband directional sampler  

DOEpatents

The Ultra-Wideband (UWB) Directional Sampler is a four port device that combines the function of a directional coupler with a high speed sampler. Two of the four ports operate at a high sub-nanosecond speed, in ``real time``, and the other two ports operate at a slow millisecond-speed, in ``equivalent time``. A signal flowing inbound to either of the high speed ports is sampled and coupled, in equivalent time, to the adjacent equivalent time port while being isolated from the opposite equivalent time port. A primary application is for a time domain reflectometry (TDR) situation where the reflected pulse returns while the outbound pulse is still being transmitted, such as when the reflecting discontinuity is very close to the TDR apparatus. 3 figs.

McEwan, T.E.

1996-05-14

22

Ultra-wideband directional sampler  

DOEpatents

The Ultra-Wideband (UWB) Directional Sampler is a four port device that combines the function of a directional coupler with a high speed sampler. Two of the four ports operate at a high sub-nanosecond speed, in "real time", and the other two ports operate at a slow millisecond-speed, in "equivalent time". A signal flowing inbound to either of the high speed ports is sampled and coupled, in equivalent time, to the adjacent equivalent time port while being isolated from the opposite equivalent time port. A primary application is for a time domain reflectometry (TDR) situation where the reflected pulse returns while the outbound pulse is still being transmitted, such as when the reflecting discontinuity is very close to the TDR apparatus.

McEwan, Thomas E. (Livermore, CA)

1996-01-01

23

Antenna design for ultra wideband radio  

E-print Network

The recent allocation of the 3.1-10.6 GHz spectrum by the Federal Communications Commission (FCC) for Ultra Wideband (UWB) radio applications has presented a myriad of exciting opportunities and challenges for design in ...

Powell, Johnna, 1980-

2004-01-01

24

Ultra Wideband InterferenceUltra Wideband Interference Effects on an AmateurEffects on an Amateur  

E-print Network

Ultra Wideband InterferenceUltra Wideband Interference Effects on an AmateurEffects on an AmateurSensitivity is important 1. http://www.arrl.org #12;Amateur Radio BandsAmateur Radio Bands MHz GHz Mid-Range Imaging Indoor · Compressed output level depends on clipping level and duty cycle · 5dB differential implies UWB signal has 30

Southern California, University of

25

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.

2012-06-01

26

Novel low-cost ultra-wideband, ultra-short-pulse transmitter with MESFET impulse-shaping circuitry for reduced distortion and improved pulse repetition rate  

Microsoft Academic Search

A new ultra-wideband, ultra-short-pulse transmitter has been developed using microstrip lines, step-recovery and Schottky diodes, MESFET, and monolithic microwave integrated circuit (MMIC) amplifier. This transmitter employs a novel MESFET impulse-shaping circuit to achieve several unique advantages, including less distortion, easy broadband matching, and increased pulse repetition rate. The transmitter produces 300-ps monocycle pulses with about 2 V peak-to-peak and a

Jeong Soo Lee; Cam Nguyen

2001-01-01

27

Nonorthogonal Pulse Position Modulation for Time-Hopping Multiple Access UWB Communications  

NASA Astrophysics Data System (ADS)

In this paper, we study the capacity and performance of nonorthogonal pulse position modulation (NPPM) for Ultra-Wideband (UWB) communication systems over both AWGN and IEEE802.15.3a channels. The channel capacity of NPPM is determined for a time-hopping multiple access UWB communication system. The error probability and performance bounds are derived for a multiuser environment. It is shown that with proper selection of the pulse waveform and modulation index, NPPM can achieve a higher capacity than orthogonal PPM, and also provide better performance than orthogonal PPM with the same throughput.

Zhang, Hao; Gulliver, T. Aaron

28

Performance of ultra-wideband communications with suboptimal receivers in multipath channels  

Microsoft Academic Search

The performance of a single-user ultra-wideband (UWB) communication system employing binary block-coded pulse-position modulation (PPM) and suboptimal receivers in multipath channels is considered. The receivers examined include a RAKE receiver with various diversity combining schemes and an autocorrelation receiver, which is used in conjunction with transmitted reference (TR) signaling. A general framework is provided for deriving the performance of these

John D. Choi; Wayne E. Stark

2002-01-01

29

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

Microsoft Academic Search

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

Claudia A. Hertzog; Farid U. Dowla; Gregory E. Dallum; Carlos E. Romero

2011-01-01

30

Free space optical ultra-wideband communications over atmospheric turbulence channels.  

PubMed

A hybrid impulse radio ultra-wideband (IR-UWB) communication system in which UWB pulses are transmitted over long distances through free space optical (FSO) links is proposed. FSO channels are characterized by random fluctuations in the received light intensity mainly due to the atmospheric turbulence. For this reason, theoretical detection error probability analysis is presented for the proposed system for a time-hopping pulse-position modulated (TH-PPM) UWB signal model under weak, moderate and strong turbulence conditions. For the optical system output distributed over radio frequency UWB channels, composite error analysis is also presented. The theoretical derivations are verified via simulation results, which indicate a computationally and spectrally efficient UWB-over-FSO system. PMID:20721053

Davaslio?lu, Kemal; Ca?iral, Erman; Koca, Mutlu

2010-08-01

31

Optimal waveforms design for ultra-wideband impulse radio sensors.  

PubMed

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. PMID:22163511

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

2010-01-01

32

A CMOS fifth-derivative Gaussian pulse generator for UWB applications  

NASA Astrophysics Data System (ADS)

A CMOS fifth-derivative Gaussian pulse generator is presented for ultra-wideband (UWB) applications. The design exhibits low power consumption, low circuit complexity, and a precise pulse shape to inherently comply with the FCC spectrum mask for indoor UWB applications without the need for a filter. The pulse generator is implemented with a 1.8-V, 0.18-?m CMOS process. The small core chip size of the pulse generator is only 217 × 121 ?m2 because of its all digital circuit design. The measured fifth-derivative Gaussian pulse has a peak-to-peak amplitude of 158 mV and a pulse width of 800 ps. The average power dissipation is 0.6 mW with a pulse repetition frequency of 50 MHz.

Jin, He; Jiang, Luo; Hao, Wang; Sheng, Chang; Qijun, Huang; Yueping, Zhang

2014-09-01

33

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

34

A high speed image transmission system for ultra-wideband wireless links  

E-print Network

Ultra-wideband (UWB) communication is an emerging technology that offers short range, high data rate wireless transmission, with low power consumption and low consumer cost. Operating in the 3.1 GHz - 10.6 GHz frequency ...

Liang, Helen He

2009-01-01

35

Ground Reflection Path Loss Based on Average Power Loss for Ultra Wideband Communications  

Microsoft Academic Search

In this paper, the ground reflection path loss based on average power loss for ultra wideband (UWB) communications is proposed. The expression is derived from the rectangular passband waveform and extension of Friis\\

Pichaya Supanakoon; Sarunya Kaewsirisin; Sathaporn Promwong; Suthichai Noppanakeepong; Jun-ichi Takada

2007-01-01

36

Robust range-based localization and motion planning under uncertainty using ultra-wideband radio  

E-print Network

The work presented in this thesis addresses two problems: accurately localizing a mobile robot using ultra-wideband (UWB) radio signals in GPS-denied environments; and planning robot trajectories that incorporate belief ...

Prentice, Samuel J. (Samuel James)

2007-01-01

37

Development of an electronically tunable ultra-wideband radar imaging sensor and its components  

E-print Network

Novel microwave transmitter and receiver circuits have been developed for implementing UWB (Ultra-Wideband) impulse radar imaging sensor operating in frequency band 0.2 to 4 GHz. with tunable operating frequency band. The fundamental system design...

Han, Jeongwoo

2006-08-16

38

Compact frequency notched ultra-wideband fractal printed slot antenna  

Microsoft Academic Search

A novel frequency notched ultra-wideband (UWB) fractal printed slot antenna is proposed. The antenna is similar in configuration to a conventional microstrip-fed wide slot antenna, however, by introducing a Koch fractal slot, not only the size of the antenna is reduced significantly but also frequency notched function is achieved. Several properties of the antenna such as impedance bandwidth, frequency notched

W. J. Lui; C. H. Cheng; H. B. Zhu

2006-01-01

39

Optical correlation of ultra-wideband signals using time-space-conversion C. Seifarth, H. Knuppertz, J. Jahns  

E-print Network

Optical correlation of ultra-wideband signals using time-space-conversion C. Seifarth, H. Knuppertz acoustic waves and deflect it at different angles depending on the temporal spectral components of the input signal. Ultra-wideband (UWB) devices as defined by the European Commission spread their RF energy

Jahns, Jürgen

40

Ultra Wideband Electromagnetic Phantoms for Antennas and Propagation Studies  

NASA Astrophysics Data System (ADS)

Ultra wideband (UWB) technologies are expected to be used in ultra-high-speed wireless personal area networks (WPAN) and wireless body area networks (WBAN). UWB human electromagnetic phantoms are useful for performance evaluation of antennas mounted in the vicinity of a human body and channel assessment when a human body blocks a propagation path. Publications on UWB phantoms, however, have been limited so far. This paper describes the development of liquid UWB phantom material (aqueous solution of sucrose) and UWB arm and torso phantoms. The UWB phantoms are not intended to evaluate a specific absorption rate (SAR) in a human body, because UWB devices are supposed to transmit at very low power and thus should pose no human hazard.

Yamamoto, Hironobu; Zhou, Jian; Kobayashi, Takehiko

41

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

42

Regression models of ultra wideband ground reflection path loss based on peak power loss  

Microsoft Academic Search

In this paper, the regression models of ultra wideband (UWB) ground reflection path loss are proposed. The UWB ground reflection path loss is defined as the ratio between the maximum amplitude of the transmitted and received signal waveforms. The polarizations of transmitted signal and ground characteristics are considered. The double and triple linear regression models are derived from the closed

Pichaya Supanakoon; Apiradee Pokang; Sathaporn Promwong; Suthichai Noppanakeepong; Jun-ichi Takada

2007-01-01

43

Short-Range Ultra-Wideband Systems UMass Antenna Lab USC UltRa Lab UC Berkeley BWRC  

E-print Network

Short-Range Ultra-Wideband Systems UMass Antenna Lab USC UltRa Lab UC Berkeley BWRC 1:15 PM: Circuit Design Panel: Bob Brodersen, Won Namgoong, Mike Chen, Ian O'Donnell, Stanley Wang Topics: UWB Low channel, UWB Performance and CMOS Impairments, Complete Asset Tracking System Panel: The UWB MURI Team 3

Southern California, University of

44

Path-loss exponents of ultra wideband signals in line-of-sight environments  

Microsoft Academic Search

The paper proposes a new ultra wideband (UWB) line-of-sight path loss formula based on the narrowband two-path (direct and ground reflected waves) model, taking into account the bandwidth of signals. The following results were derived from numerical calculations: (1) UWB signals suffer less interference fading than narrowband signals; (2) UWB path loss exponents change approximately to 2 to 4 around

Shunsuke Sato; Takehiko Kobayashi

2004-01-01

45

Performance Evaluation of a 60-GHz Multi-band OFDM (MB-OFDM) Ultra-Wideband Radio-Over-Fibre System  

E-print Network

Performance Evaluation of a 60-GHz Multi-band OFDM (MB-OFDM) Ultra-Wideband Radio-Over-Fibre System O Omomukuyo and J E Mitchell University College London Abstract: In this paper, we present-Over-Fibre (RoF) system for Ultra- Wideband (UWB) applications in the 60-GHz radio band. We have made use of two

Haddadi, Hamed

46

47 CFR 15.507 - Marketing of UWB equipment.  

Code of Federal Regulations, 2013 CFR

... false Marketing of UWB equipment. 15.507 Section 15.507 Telecommunication FEDERAL COMMUNICATIONS...DEVICES Ultra-Wideband Operation § 15.507 Marketing of UWB equipment. In some cases, the operation of UWB devices is...

2013-10-01

47

47 CFR 15.507 - Marketing of UWB equipment.  

Code of Federal Regulations, 2011 CFR

... false Marketing of UWB equipment. 15.507 Section 15.507 Telecommunication FEDERAL COMMUNICATIONS...DEVICES Ultra-Wideband Operation § 15.507 Marketing of UWB equipment. In some cases, the operation of UWB devices is...

2011-10-01

48

47 CFR 15.507 - Marketing of UWB equipment.  

Code of Federal Regulations, 2012 CFR

... false Marketing of UWB equipment. 15.507 Section 15.507 Telecommunication FEDERAL COMMUNICATIONS...DEVICES Ultra-Wideband Operation § 15.507 Marketing of UWB equipment. In some cases, the operation of UWB devices is...

2012-10-01

49

47 CFR 15.507 - Marketing of UWB equipment.  

Code of Federal Regulations, 2010 CFR

... false Marketing of UWB equipment. 15.507 Section 15.507 Telecommunication FEDERAL COMMUNICATIONS...DEVICES Ultra-Wideband Operation § 15.507 Marketing of UWB equipment. In some cases, the operation of UWB devices is...

2010-10-01

50

Ultra-wideband digital baseband  

E-print Network

The FCC approved the use of Ultra-wideband signals for communication purposes in February 2002 in the band from 3.1GHz to 10.6GHz, effectively opening 7.5GHz of free unlicensed bandwidth. There are two main constraints for ...

Blázquez-Fernández, Raúl, 1975-

2006-01-01

51

ICUWB 2009 to Focus on Microvave and Millimeter Wave Band Technology, IEEE International Conference on Ultra-Wideband will Meet on 9–11 September 2009 in Vancouver  

Microsoft Academic Search

IEEE International Conference on Ultra-Wideband Will Meet on 9 - 11 September 2009 in Vancouver In Vancouver on 9-11 September, the 2009 IEEE International Conference on Ultra-Wideband will center around the topic of UWB transmission in micro-wave and millimeter wave bands and over power lines. It will focus on the latest advances in UWB technology, current and future applications ranging

Lutz Lampe

2008-01-01

52

UWB car attenuation measurements  

Microsoft Academic Search

In the European regulatory domain the CEPT ECC working group TG3 on ultra wideband (UWB) has developed a broad framework for the regulation of the deployment of UWB devices in Europe. In the first draft of the regulation the deployment of UWB will be strictly restricted to indoor usage, prohibiting usage in cars, trains and planes in order to guarantee

F. Berens; H. Dunger; S. Czarnecki; T. Bock; R. Reuter; S. Zeisberg; J. Weber; J. F. Guasch

2007-01-01

53

A low power, high dynamic-range, broadband variable gain amplifier for an ultra wideband receiver  

E-print Network

is designed for high frequency and low power communication applications, such as an Ultra Wideband (UWB) receiver system. The gain can be programmed from 0dB to 42dB in 2dB increments with -3dB bandwidth greater than 425MHz for the entire range of gain. The 3...

Chen, Lin

2007-09-17

54

Response to FCC 98-208 notice of inquiry in the matter of revision of part 15 of the commission's rules regarding ultra-wideband transmission systems  

Microsoft Academic Search

In general, Micropower Impulse Radar (MIR) depends on Ultra-Wideband (UWB) transmission systems. UWB technology can supply innovative new systems and products that have an obvious value for radar and communications uses. Important applications include bridge-deck inspection systems, ground penetrating radar, mine detection, and precise distance resolution for such things as liquid level measurement. Most of these UWB inspection and measurement

Morey

1998-01-01

55

Optimal Channel Energy Capture for Ultra-Wideband Transmitted Reference Systems in Clustered Channels  

Microsoft Academic Search

Due to the large signal bandwidth of an ultra-wideband (UWB) transmitted reference (TR) system, the clustering channel statistics, as defined in the IEEE 802.15.3a channel models, should be taken into account in performance characterization. In this paper, we address the optimal mean channel energy capture for the maximal signal-to-interference-plus-noise ratio (SINR) regarding the special UWB channel statistics. It is analytically

Chi-Hsuan Hsieh; Wei-De Wu; Chi-Chao Chao

2010-01-01

56

Impact of Optical Transmission on Multiband OFDM Ultra-Wideband Wireless System With Fiber Distribution  

Microsoft Academic Search

Multiband (MB) orthogonal frequency-division multiplexing (OFDM) ultra-wideband (UWB) wireless, which provides high data rate access, is required to be distributed by using optical fiber. The performance of MB-OFDM UWB over fiber transmission system is investigated considering optical modulation and demodulation impact. Theoretical analysis of the effect of fiber dispersion, optical transmitter, and optical receiver response on system performance is carried

Meer Nazmus Sakib; Bouchaib Hraimel; Xiupu Zhang; Mohmoud Mohamed; Wei Jiang; Ke Wu; Dongya Shen

2009-01-01

57

Three-ray path loss based on peak power loss for ultra wideband impulse radio systems  

Microsoft Academic Search

Path loss is important parameter to analyze and design link budget. For indoor environment, there is fading that occurs in path loss. Therefore, accurate path loss model, which is considered fading, is necessary. In this paper, three-ray path loss based on peak power loss is proposed for ultra wideband impulse radio (UWB-IR) systems. The rectangular passband is used as UWB-IR

Pichaya Supanakoon; Saksit Chaiyapong; Sathaporn Promwong; Jun-ichi Takada

2011-01-01

58

A novel multi-antenna impulse radio UWB transceiver for broadband high-throughput 4G WLANs  

Microsoft Academic Search

In the last years, a lot of attention has been devoted to both multi-antenna systems with space-time orthogonal block coding (STOBC) and ultra wideband (UWB) transceivers based on impulse-radio (IR) technologies. In this short contribution we anticipate the architecture of a novel transceiver merging both multi-antenna and pulse position modulation (PPM) IR-UWB techniques and then we test the performance in

Enzo Baccarelli; Mauro Biagi; Cristian Pelizzoni; Pierfrancesco Bellotti

2004-01-01

59

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Technical requirements for hand held UWB systems. 15.519 Section 15.519...Ultra-Wideband Operation § 15.519 Technical requirements for hand held UWB systems. (a) UWB devices...

2010-10-01

60

Multi-band OFDM UWB receiver with narrowband interference suppression  

E-print Network

A multi band orthogonal frequency division multiplexing (MB-OFDM) compatible ultra wideband (UWB) receiver with narrowband interference (NBI) suppression capability is presented. The average transmit power of UWB system is limited to -41.3 dBm...

Kelleci, Burak

2009-05-15

61

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

62

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. PMID:16705798

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

2005-01-01

63

Abstract--This paper investigates a ranging method employing Ultra wideband (UWB) pulses under the existence of the line of  

E-print Network

applications such as see-through-the-wall, medical imaging, and collision avoidance. Previous ranging reduces noise of the received signals corrupted by the statistically zero mean AWGN. The proposed method error due to imperfect TOA estimation from imperfect synchronization. Sources of inter

Ha, Dong S.

64

SoC CMOS UWB Pulse Radar Sensor for Contactless Respiratory Rate Monitoring.  

PubMed

An ultra wideband (UWB) system-on-chip radar sensor for respiratory rate monitoring has been realized in 90 nm CMOS technology and characterized experimentally. The radar testchip has been applied to the contactless detection of the respiration activity of adult and baby. The field operational tests demonstrate that the UWB radar sensor detects the respiratory rate of person under test (adult and baby) associated with sub-centimeter chest movements, allowing the continuous-time non-invasive monitoring of hospital patients and other people at risk of obstructive apneas such as babies in cot beds, or other respiratory diseases. PMID:23852548

Zito, D; Pepe, D; Mincica, M; Zito, F; Tognetti, A; Lanata, A; De Rossi, Danilo

2011-12-01

65

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

66

MMSE decision feedback equalization of pulse position modulated signals  

Microsoft Academic Search

We propose a minimum mean squared error (MMSE) decision feedback equalizer (DFE) for pulse position modulated (PPM) signals in the presence of intersymbol interference (ISI). While traditional uses of PPM may not have ISI, PPM is a candidate modulation scheme for ultra wideband (UWB), and may experience ISI in that application. First, we review the previous work on the subject

A. G. Klein

2004-01-01

67

Short-Range Ultra-Wideband Systems UMass Antenna Lab USC UltRa Lab UC Berkeley BWRC  

E-print Network

Short-Range Ultra-Wideband Systems UMass Antenna Lab USC UltRa Lab UC Berkeley BWRC MURI Review Research Effort -- Bob Scholtz 9:20 AM: Algorithm and System Architecture Studies Panel: Keith Chugg, Capacity Limits of UWB Impulse Radios 10:35 AM: Break 10:45 AM: Antennas and Propagation Topics: Simulation

Southern California, University of

68

Ultra-Wideband Microwave Imaging of Heterogeneities  

E-print Network

-time imaging, ground penetrating radar, ultra-wideband imaging, migration Corresponding Author: Department and the other is the employment of ground penetrating radar (GPR) for imaging the near surface of the earth

Boyer, Edmond

69

On the Array Performance of Printed, Ultra-Wideband “Eared” Antennas  

Microsoft Academic Search

The performance of an ultra-wideband (UWB) radiator is examined in a 15-element linear-array environment. The numerically predicted array impedance is validated by means of physical measurements. The broadside scanned radiation patterns of the array are measured and proven to be extremely favorable. A zoom-in on the measured elementary radiation patterns is employed for evidencing the effect of embedding the radiator

F. Muge Tanyer-Tigrek; Ioan E. Lager; Leonardus P. Ligthart

2011-01-01

70

A fully differential IR-UWB front-end for noncoherent communication and localization  

Microsoft Academic Search

This paper presents a 3.1-10.6 GHz ultra-wideband transmitter\\/receiver chipset for non-coherent communication and localization applications. Its fully differential topology fits promising balanced UWB antennas, and eases packaging. The transmitter uses a cross-coupled oscillator core transiently turned on by a current spike. It consumes 6 mW at 100 MHz impulse repetion rate, including the on-chip pulse shaping circuitry. The energy-detecting receiver

Dayang Lin; Andreas Trasser; Hermann Schumacher

2011-01-01

71

Ultra-wideband impedance sensor  

DOEpatents

The ultra-wideband impedance sensor (UWBZ sensor, or Z-sensor) is implemented in differential and single-ended configurations. The differential UWBZ sensor employs a sub-nanosecond impulse to determine the balance of an impedance bridge. The bridge is configured as a differential sample-and-hold circuit that has a reference impedance side and an unknown impedance side. The unknown impedance side includes a short transmission line whose impedance is a function of the near proximity of objects. The single-ended UWBZ sensor eliminates the reference side of the bridge and is formed of a sample and hold circuit having a transmission line whose impedance is a function of the near proximity of objects. The sensing range of the transmission line is bounded by the two-way travel time of the impulse, thereby eliminating spurious Doppler modes from large distant objects that would occur in a microwave CW impedance bridge. Thus, the UWBZ sensor is a range-gated proximity sensor. The Z-sensor senses the near proximity of various materials such as metal, plastic, wood, petroleum products, and living tissue. It is much like a capacitance sensor, yet it is impervious to moisture. One broad application area is the general replacement of magnetic sensors, particularly where nonferrous materials need to be sensed. Another broad application area is sensing full/empty levels in tanks, vats and silos, e.g., a full/empty switch in water or petroleum tanks. 2 figs.

McEwan, T.E.

1999-03-16

72

Ultra-wideband impedance sensor  

DOEpatents

The ultra-wideband impedance sensor (UWBZ sensor, or Z-sensor) is implemented in differential and single-ended configurations. The differential UWBZ sensor employs a sub-nanosecond impulse to determine the balance of an impedance bridge. The bridge is configured as a differential sample-and-hold circuit that has a reference impedance side and an unknown impedance side. The unknown impedance side includes a short transmission line whose impedance is a function of the near proximity of objects. The single-ended UWBZ sensor eliminates the reference side of the bridge and is formed of a sample and hold circuit having a transmission line whose impedance is a function of the near proximity of objects. The sensing range of the transmission line is bounded by the two-way travel time of the impulse, thereby eliminating spurious Doppler modes from large distant objects that would occur in a microwave CW impedance bridge. Thus, the UWBZ sensor is a range-gated proximity sensor. The Z-sensor senses the near proximity of various materials such as metal, plastic, wood, petroleum products, and living tissue. It is much like a capacitance sensor, yet it is impervious to moisture. One broad application area is the general replacement of magnetic sensors, particularly where nonferrous materials need to be sensed. Another broad application area is sensing full/empty levels in tanks, vats and silos, e.g., a full/empty switch in water or petroleum tanks.

McEwan, Thomas E. (Livermore, CA)

1999-01-01

73

47 CFR 15.517 - Technical requirements for indoor UWB systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Technical requirements for indoor UWB systems. 15.517 Section 15.517 Telecommunication...Ultra-Wideband Operation § 15.517 Technical requirements for indoor UWB systems. (a) Operation under the...

2010-10-01

74

Compact Electromagnetic Bandgap Structures for Notch Band in Ultra-Wideband Applications  

PubMed Central

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

75

Ultra-wideband microwave imaging of breast cancer tumors via Bayesian inverse scattering  

NASA Astrophysics Data System (ADS)

We develop a new algorithm for ultra-wideband (UWB) microwave imaging of breast cancer tumors using Bayesian inverse scattering. A key feature of the proposed algorithm is that constitutive properties of breast tissues are reconstructed from scattered UWB microwave signals together with the confidence level of the reconstruction. Having such confidence level enables minimization of both false alarms and missed detections. Results from the application of the proposed algorithm demonstrate the accuracy in estimating both location and permittivity of breast tumors without the need for a priori knowledge of pointwise properties of the background breast tissue.

Fouda, A. E.; Teixeira, F. L.

2014-02-01

76

Augmented reality using ultra-wideband radar imagery  

NASA Astrophysics Data System (ADS)

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 UWB SAR radar for proof-of-concept demonstration in detecting obstacles for autonomous navigation, detecting concealed targets (mines, etc.), and mapping internal building structures to locate enemy activity. Although the low-frequency UWB radar technology offers valuable information to complement other technologies due to its penetration capability, it is very difficult to comprehend the radar imagery and correlate the detection list from the radar with the objects in the real world. Using augmented reality (AR) technology, we can superimpose the information from the radar onto the video image of the real world in real-time. Using this, Soldiers would view the environment and the superimposed graphics (SAR imagery, detection locations, digital map, etc.) via a standard display or a head-mounted display. The superimposed information would be constantly changed and adjusted for every perspective and movement of the user. ARL has been collaborating with ITT Industries to implement an AR system that integrates the video data captured from the real world and the information from the UWB radar. ARL conducted an experiment and demonstrated the real-time geo-registration of the two independent data streams. The integration of the AR sub-system into the radar system is underway. This paper presents the integration of the AR and SAR systems. It shows results that include the real-time embedding of the SAR imagery and other information into the video data stream.

Nguyen, Lam; Koenig, Francois; Sherbondy, Kelly

2011-06-01

77

Software-Defined Ultra-wideband Radio Communications: A New RF Technology for Emergency Response Applications  

SciTech Connect

Reliable wireless communication links for local-area (short-range) and regional (long-range) reach capabilities are crucial for emergency response to disasters. Lack of a dependable communication system can result in disruptions in the situational awareness between the local responders in the field and the emergency command and control centers. To date, all wireless communications systems such as cell phones and walkie-talkies use narrowband radio frequency (RF) signaling for data communication. However, the hostile radio propagation environment caused by collapsed structures and rubble in various disaster sites results in significant degradation and attenuation of narrowband RF signals, which ends up in frequent communication breakdowns. To address the challenges of reliable radio communication in disaster fields, we propose an approach to use ultra-wideband (UWB) or wideband RF waveforms for implementation on Software Defined Radio (SDR) platforms. Ultra-wideband communications has been proven by many research groups to be effective in addressing many of the limitations faced by conventional narrowband radio technologies. In addition, LLNL's radio and wireless team have shown significant success in field deployment of various UWB communications system for harsh environments based on LLNL's patented UWB modulation and equalization techniques. Furthermore, using software defined radio platform for UWB communications offers a great deal of flexibility in operational parameters and helps the radio system to dynamically adapt itself to its environment for optimal performance.

Nekoogar, F; Dowla, F

2009-10-19

78

Method for high precision local positioning radar using an ultra wideband technique  

Microsoft Academic Search

In this paper, a novel approach for a high precision local positioning radar using an ultra wideband technique is presented. The concept is based on the standard FMCW (frequency modulated continuous wave) radar principle combined with short pulses to fulfill the emission limits given by the official regulatory authorities. With this concept, a high accuracy in dense multipath indoor environments

Benjamin Waldmann; Robert Weigel; Peter Gulden

2008-01-01

79

ULTRA WIDEBAND INTERFERENCE EFFECTS ON AN AMATEUR RADIO RECEIVER R. D. Wilson, R. D. Weaver, M.-H. Chung and R. A. Scholtz  

E-print Network

, which also provided samples of their standard re- ceiver test procedures. Sophisticated radio amateursULTRA WIDEBAND INTERFERENCE EFFECTS ON AN AMATEUR RADIO RECEIVER R. D. Wilson, R. D. Weaver, M. Testing was performed at the University of Southern California (USC), using the experi- mental UWB

Southern California, University of

80

Analysis of Ultra-Wideband Printed Planar Quasi-Monopole Antennas Using the Theory of Characteristic Modes  

Microsoft Academic Search

This paper presents an analysis of ultra-wideband (UWB) printed planar quasi-monopole antennas using the theory of characteristic modes. It is shown that the modal voltage-standing-wave ratio, mode current distribution, and modal significance provide deeper physical insight into the operating mechanisms of these popular types of antennas. Using the printed planar bevel-shaped quasi-monopole antenna as an example, we characterize the antenna's

Weixia Wu; Y. P. Zhang

2010-01-01

81

Analysis and Design of Two Low-Power Ultra-Wideband CMOS Low-Noise Amplifiers With Out-Band Rejection  

Microsoft Academic Search

Two 3-5-GHz low-power ultra-wideband (UWB) low-noise amplifiers (LNAs) with out-band rejection function using 0.18- ??m CMOS technology are presented. Due to the Federal Communications Commission's stringent power-emission limitation at the transmitter, the received signal power in the UWB system is smaller than those of the close narrowband interferers such as the IEEE 802.11 a\\/b\\/g wireless local area network, and the

Ching-Piao Liang; Pei-Zong Rao; Tian-Jian Huang; Shyh-Jong Chung

2010-01-01

82

The effects of the human body on UWB signal propagation in an indoor environment  

Microsoft Academic Search

Ultra-wideband (UWB) communication systems are investigated for their ability to operate in dense multipath environments. While a great deal of time and effort has been spent characterizing both the indoor and outdoor UWB channels, the effects of human body interaction with a close proximity UWB antenna remains unexplored. Measurements of a commercially available UWB antenna performance in an anechoic chamber

T. B. Welch; Randall L. Musselman; Bomono A. Emessiene; Phillip D. Gift; Daniel K. Choudhury; Derek N. Cassadine; Scott M. Yano

2002-01-01

83

Simulation Study of Ultra-Wideband Communication System Tefera Tibebe  

E-print Network

in frequency and thus their immunity to multipath effects have attracted growing interest as a viable candidate for short range high speed indoor radio communication services. In section 2, the technology basics of UWB, Gaussian mono-pulse & poly-cycle, their properties in the Time & Frequency domains UWB signals are produced

Haddadi, Hamed

84

Free Space Path Loss of UWB Communications  

Microsoft Academic Search

Although the Friis' formula is widely used to calculate the free space path loss of narrowband communications, it is considered only single frequency. Therefore, it should be extended to calculate the free space path loss of ultra wideband (UWB) communications by considering the frequency bandwidth. In this paper, the free space path loss of UWB communications is studies. The Friis'

Pichaya Supanakoon; Sathit Aroonpraparat; Sathaporn Promwong; Jun-ichi Takada

85

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

86

Recent trends and advances in UWB positioning  

Microsoft Academic Search

Since the ruling of the Federal Communications Commission (FCC) in the United States to open up the spectrum from 3.1-10.6 GHz for ultra wideband (UWB) applications in 2002, interest in the use of UWB for localization outside of military applications has skyrocketed. The multi-purpose nature of UWB for localization and also high or low data rate communication make it robust

Mohamed R. Mahfouz; Aly E. Fathy; Michael J. Kuhn; Yahzou Wang

2009-01-01

87

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

Microsoft Academic Search

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

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

2009-01-01

88

Draft Submitted to J-SAC Circuit Modeling Methodology for UWB Omnidirectional Small  

E-print Network

Draft Submitted to J-SAC - 1 - Circuit Modeling Methodology for UWB Omnidirectional Small Antennas Submitted to J-SAC - 2 - Circuit Modeling Methodology for UWB Omnidirectional Small Antennas Stanley B. T to J-SAC - 3 - I. INTRODUCTION In 2002, the FCC released the use of Ultra-wideband (UWB) transmission

Southern California, University of

89

Ultra-Wideband OFDM Radar and Communication System.  

E-print Network

??This paper examines the possibility of a dual use radar and communication systembased on ultra-wideband orthogonal frequency division multiplexed (OFDM)waveforms. Theory for utilizing OFDM as… (more)

Schuerger, Jonathan Paul

2009-01-01

90

Waveform Analysis of UWB GPR Antennas  

PubMed Central

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

91

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

92

On UWB beamforming  

Microsoft Academic Search

Ultra-Wideband (UWB) communication systems and Multi-Input-Multi-Output (MIMO) techniques rank among the few emerging key technologies in wireless communications. For that reason the marriage of these two complementary approaches should deserve attention. Apparently, the extremely large ultra-wide bandwidth creates rich multipath diversity which calls, at a first glance, additional antenna elements into question. However, another point of view is as follows.

T. Kaiser

2004-01-01

93

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

94

Free space link budget evaluation of UWB-IR systems  

Microsoft Academic Search

Ultra wideband impulse radio (UWB-IR) technology is an ideal candidate for wireless networks that can be utilized for short-range, high-speed, low power, and low cost indoor applications. The link budget of the free space propagation loss is usually estimated by using Friis' transmission formula. However, it is not directly applicable to ultra wideband impulse radio transmission systems, in particular the

Sathaporn Promwong; Wataru Hachitani; Jun-ichi Takada

2004-01-01

95

A novel low-profile log-periodic ultra wideband feed for the dual-reflector antenna of US-SKA  

Microsoft Academic Search

We present a novel low-profile log-periodic ultra wideband (UWB) dipole antenna referred to as the Chalmers feed. The simulated results presented show that the antenna has low input reflection coefficient, low cross-polarization, constant beam width and constant phase center position over more than a decade bandwidth. The antenna can be enclosed in a volume of 0.5?L, · 0.5?L · 0.15?L

R. Olsson; P.-S. Kilda; S. Weinreb

2004-01-01

96

An energy-efficient all-digital UWB transmitter employing dual capacitively-coupled pulse-shaping drivers  

E-print Network

This paper presents an all-digital, non-coherent, pulsed-UWB transmitter. By exploiting relaxed center frequency tolerances in non-coherent wideband communication, the transmitter synthesizes UWB pulses from an energy-efficient, ...

Mercier, Patrick Philip

97

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

98

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. PMID:21970578

2011-01-01

99

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

PubMed

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. PMID:21970578

Kim, Nammoon; Kim, Youngok

2011-01-01

100

Performance of Ultra-Wideband Correlator Receiver Using Gaussian Monocycles  

E-print Network

to be the most competitive techniques for indoor WLAN or WPAN communications [1] [2]. TH-UWB can be regarded the signal's low duty cycle and PPM-TH modulation method, and is exhibited by the autocorrelation function codes, but not the shaping pulse, that determines the performance. Due to their effective simultaneous

Abhayapala, Thushara D.

101

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.

102

UWB module with antenna using organic substrates  

Microsoft Academic Search

This paper presents the ultra wideband (UWB) module which contains an antenna, switches and a low noise amplifier (LNA). In order to accomplish small size and low cost, the antenna is designed using organic substrates and other parts are fabricated on the same printed circuit board (PCB) as the antenna. Size of the antenna is 20 mm × 15 mm

Koichiro Gomi; Masaaki Ishida; Shigeru Hiura

2005-01-01

103

UWB module with antenna using organic substrates  

Microsoft Academic Search

This paper presents the ultra wideband (UWB) module which contains an antenna, switches and a low noise amplifier (LNA). In order to accomplish small size and low cost, the antenna is designed using organic substrates and other parts are fabricated on the same printed circuit board (PCB) as the antenna. Size of the antenna is 20 mm times 15 mm

Koichiro Gomi; Masaaki Ishida; Shigeru Hiura

2005-01-01

104

UWB integration into heterogeneous access networks  

Microsoft Academic Search

The purpose of this paper is to provide the reader with a vision of the current status of the integration of the Ultra-Wideband (UWB) technology into the heterogeneous access networks. Three different fields have been considered to perform this integration process: user devices, access network equipment and location-aware services. Nowadays user terminals and network devices are equipped with multiple radio

Ana Sierra; Juan Choliz; Pierre Cluzeaud; Emil Slusanschi

2011-01-01

105

Technical note: a novel approach to the detection of estrus in dairy cows using ultra-wideband technology.  

PubMed

Detection of estrus is a key determinant of profitability of dairy herds, but estrus is increasingly difficult to observe in the modern dairy cow with shorter duration and less-intense estrus. Concurrent with the unfavorable correlation between milk yield and fertility, estrus-detection rates have declined to less than 50%. We tested ultra-wideband (UWB) radio technology (Thales Research & Technology Ltd., Reading, UK) for proof of concept that estrus could be detected in dairy cows (two 1-wk-long trials; n=16 cows, 8 in each test). The 3-dimensional positions of 12 cows with synchronized estrous cycles and 4 pregnant control cows were monitored continuously using UWB mobile units operating within a network of 8 base units for a period of 7d. In the study, 10 cows exhibited estrus as confirmed by visual observation, activity monitoring, and milk progesterone concentrations. Automated software was developed for analysis of UWB data to detect cows in estrus and report the onset of estrus in real time. The UWB technology accurately detected 9 out of 10 cows in estrus. In addition, UWB technology accurately confirmed all 6 cows not in estrus. In conclusion, UWB technology can accurately detect estrus and hence we have demonstrated proof of concept for a novel technology that has significant potential to improve estrus-detection rates. PMID:23910546

Homer, E M; Gao, Y; Meng, X; Dodson, A; Webb, R; Garnsworthy, P C

2013-10-01

106

Photonic generation of millimeter-wave ultra-wideband signal using phase modulation to intensity modulation conversion and frequency up-conversion  

NASA Astrophysics Data System (ADS)

We propose and experimentally demonstrate the generation of a pair of polarity-reversed 24 GHz millimeter-wave (MMW) ultra-wideband (UWB) monocycles. The scheme is realized by using delay interferometer (DI) based phase modulation to intensity modulation (PM-IM) conversion and carrier suppression modulation (CSM) based frequency up-conversion. The phase modulation is realized by using either electro-optic phase modulator (EOPM) or cross phase modulation (XPM) in semiconductor optical amplifier (SOA), which is an all-optical approach to obtaining baseband UWB signals, respectively. After frequency up-converted by using CSM in a Mach-Zehnder modulator (MZM), a pair of polarity-reversed 24 GHz MMW-UWB signals complying with the Federal Communication Committee (FCC) requirements is generated. The bi-phase modulation (BPM) of 24 GHz MMW-UWB signals can also be realized by electrically switching the bias voltage of delay interferometer.

Yu, Yuan; Dong, Jianji; Li, Xiang; Zhang, Xinliang

2012-04-01

107

Waveform Optimizations for Ultra-Wideband Radio Systems  

Microsoft Academic Search

Solutions are presented for various optimizations of transient waveforms and signals used in ultra-wideband radio systems. These include the transmit antenna generator waveform required to maximize receive antenna voltage amplitude (with bounded input energy), the transmit antenna generator waveform that provides the \\

David M. Pozar

108

An 8GHz Ultra Wideband Transceiver Prototyping Testbed  

Microsoft Academic Search

Software defined radios have the potential of changing the fundamental usage model of wireless communications devices, but the capabilities of these transceivers are often limited by the speed of the underlying processors and FPGAs. This paper presents a testbed for the design of an impulse-based ultra wideband communication system. The transceiver is being developed using software\\/reconfigurable radio concepts and will

Deepak Argarwal; Christopher R. Anderson; Peter M. Athanas

2005-01-01

109

On the Operating Principles of UWB, CPW-Fed Printed Antennas  

Microsoft Academic Search

The working principles of coplanar-waveguide (CPW) -fed, ultra-wideband (UWB) printed antennas are investigated. The behavior of the current distributions at different frequencies are examined. The modifications in the current distributions when the phase of the currents changes lead us to some conclusions on the behavior of UWB antennas.

F. Muge Tanyer-Tigrek; A. Hizal; I. E. Lager; Leonardus P. Ligthart

2010-01-01

110

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. PMID:22163498

Thiel, Florian; Kosch, Olaf; Seifert, Frank

2010-01-01

111

Matched filter design optimisation for UWB receiver for sensor network application  

NASA Astrophysics Data System (ADS)

Ultra Wideband (UWB) communications is one of the possible solutions for future wireless personal area network (WPAN) applications. The Federal Communications Commission (FCC), in the USA, allocated 7.5 GHz of unlicensed frequency bandwidth from 3.1 GHz to 10.6 GHz for UWB communication. It is an available spectrum which can be utilised for data communication using different technologies complying with FCC regulations. This paper presents a brief overview of the world wide regulations and Institute of Electrical and Electronic Engineers (IEEE) standardisation updates for UWB. It also focuses on the wireless sensor network application and the use of UWB communications in biomedical sensor networks. The paper aims at the design and implementation of an optimised pulsed matched filter (OPMF) used in the digital backend of a UWB radio. The optimisations are performed at the architectural and circuit level in order to reduce hardware complexity and reduced power. The OPMF is successfully implemented using the application specific integrated circuit (ASIC) design methodology and the results are compared with those obtained in previous implementation. The OPMF implementation presented in this paper yields improved characteristics such as reduction in area, almost 25% power reduction and better timing.

Naik, Rohit; Singh, Jugdutt; Veljanovski, Ronny

2005-12-01

112

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

113

MURI Research Review Short-Range Ultra-Wideband Systems  

E-print Network

University of Massachusetts: Dave Pozar, Dan Schaubert, Dennis Goeckel Wednesday, August 20, 2003 Old Town Simulation of UWB Antennas and Circuits -- Schaubert UWB Link Budgets -- Pozar Antennas for UWB -- Pozar Optimal Waveform Studies -- Pozar UWB Synthesizer Project -- Scholtz/Namgoong/Pozar 12:00 PM: Lunch 1

Southern California, University of

114

A novel UWB bandpass filter using highpass and lowpass filters  

Microsoft Academic Search

A Novel microstrip ultra-wideband (UWB) bandpass filter (BPF) is presented, which is realized by cascading a three pole highpass filter and a five pole lowpass filter. The highpass filter consists of an improved dumbbell shaped defected ground structure (DGS) and two grounded stubs, while the lowpass filter is realized by an improved dumbbell shaped DGS, a conventional dumbbell shaped DGS

Wanchun Tang; Songmao Yang; Xiaoke Wang; Cheng Wang; Y. Leonard Chow

2012-01-01

115

A new FSS design proposal for UWB applications  

Microsoft Academic Search

This work presents a new proposal for Frequency Selective Surface (FSS) design for Ultra-Wideband (UWB) applications. The new FSSs consist of an array composed by the association of two patch elements per cell: a square loop and a crossed dipole. These structures are called Crossed Loops and have the objective of increasing the bandwidth of the square loop and the

R. M. S. Cruz; A. G. D'Assunao; P. H. da F Silva

2010-01-01

116

An accurate and robust algorithm for detection of heart and respiration rates using an impulse based UWB signal  

Microsoft Academic Search

The purpose of this paper is to introduce an accurate algorithm to detect respiration rate and heart beat using an Ultra-Wideband (UWB) signal. One important issue to consider for obtaining precise results is the right selection of measurement parameters in UWB system. In this work the impact of these parameters in detecting respiration rate and heart beat are studied and

Mehran Baboli; Azadeh Sharafi; Alireza Ahmadian; M. S. Nambakhsh

2009-01-01

117

Cooperative UWB Body Area Networking: Channel Measurement and Diversity Analysis  

Microsoft Academic Search

We explore the application of cooperative commu- nications in ultra-wideband (UWB) wireless body area networks (WBANs). Firstly, time-domain UWB channel measurements are presented for a sitting human subject. Important channel para- meters such as the pathloss, power variation, power delay profile (PDP), and effective received power (ERP) cross-correlation are extracted and statistically analyzed. Armed with the model preliminaries, an intuitive

Yifan Chen; Jianqi Teo; Joshua Lai; Erry Gunawan; Kaysoon Low; Cheongboon Soh; Predrag B. Rapajic

2008-01-01

118

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

119

All-optical binary phase-coded UWB signal generation using DWDM-based multi-channel frequency discriminator  

NASA Astrophysics Data System (ADS)

A simple all-optical binary phase-coded ultra-wideband (UWB) signal generation scheme only using a DWDM-based multi-channel optical frequency discriminator is proposed and demonstrated. In the proposed scheme, the CW lights emitted from a laser array are modulated in a phase modulator driven by electrical Gaussian pulses, and then are sent to a DWDM used as a multi-channel optical frequency discriminator, in which phase modulation to intensity modulation (PM-IM) conversions are performed, and by locating the phase-modulated light wavelengths at the positive or negative slopes of the DWDM transmission spectra, delaying and recombining each channel signal, binary phase-coded UWB codes are generated. We numerically demonstrate encode and decode process of binary phase-coded UWB signals with a code length of 4, operating at 625 Mbit/s. In addition, binary phase-coded UWB signal transmission in fiber link was also numerically investigated. Our proposed system has potential application in future multi-user UWB-over-fiber communication systems.

Tan, Long-Sheng; Wang, Fei; Ma, Huan; Hu, Qiang; Zhao, Xiao-Fang

2014-02-01

120

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. PMID:24307880

2013-01-01

121

CMOS Integrated Circuit Design for Ultra-Wideband Transmitters and Receivers  

E-print Network

makes the CMOS circuit capable of handling signal at multi-giga herz. However, some design challenges still remain to be solved. Unlike regular narrow band signal, the UWB signal is discrete pulse instead of continuous wave (CW), which results...

Xu, Rui

2010-10-12

122

Response to FCC 98-208 notice of inquiry in the matter of revision of part 15 of the commission's rules regarding ultra-wideband transmission systems  

SciTech Connect

In general, Micropower Impulse Radar (MIR) depends on Ultra-Wideband (UWB) transmission systems. UWB technology can supply innovative new systems and products that have an obvious value for radar and communications uses. Important applications include bridge-deck inspection systems, ground penetrating radar, mine detection, and precise distance resolution for such things as liquid level measurement. Most of these UWB inspection and measurement methods have some unique qualities, which need to be pursued. Therefore, in considering changes to Part 15 the FCC needs to take into account the unique features of UWB technology. MIR is applicable to two general types of UWB systems: radar systems and communications systems. Currently LLNL and its licensees are focusing on radar or radar type systems. LLNL is evaluating MIR for specialized communication systems. MIR is a relatively low power technology. Therefore, MIR systems seem to have a low potential for causing harmful interference to other users of the spectrum since the transmitted signal is spread over a wide bandwidth, which results in a relatively low spectral power density.

Morey, R M

1998-12-08

123

Radiated emission of breath monitoring system based on UWB pulses in spacecraft modules  

Microsoft Academic Search

The paper describes some EMC aspects related to a UWB radar for monitoring astronauts breathing activity. Compliance to EMC space standards forces some design aspects, in particular the peak voltage and the pulse waveform. Moreover some simulations were carried out to consider realistic operating condition. In the first case the interference towards a victim wifi circuit was analyzed, in the

P. Russo; V. Mariani Primiani; A. De Leo; G. Cerri

2012-01-01

124

Ultra-wideband Location Authentication for Item Tracking  

SciTech Connect

International safeguards is increasingly utilizing unattended and remote monitoring methods to improve inspector efficiency and the timeliness of diversion detection. Item identification and tracking has been proposed as one unattended remote monitoring method, and a number of radio-frequency (RF) technologies have been proposed. When utilizing location information for verification purposes, strong assurance of the authenticity of the reported location is required, but most commercial RF systems are vulnerable to a variety of spoofing and relay attacks. ORNL has developed a distance bounding method that uses ultra-wideband technology to provide strong assurance of item location. This distance bounding approach can be coupled with strong symmetric key authentication methods to provide a fully authenticable tracking system that is resistant to both spoofing and relay attacks. This paper will discuss the overall problems associated with RF tracking including the common spoofing and relay attack scenarios, the ORNL distance bounding approach for authenticating location, and the potential applications for this technology.

Rowe, Nathan C [ORNL; Kuhn, Michael J [ORNL; Stinson, Brad J [ORNL; Holland, Stephen A [ORNL

2012-01-01

125

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

126

Image Reconstruction Algorithms for UWB Pulse Radar Systems Toru SATOa)  

E-print Network

deformation model 2 2 (x, y) (x, y) = 0 (x, y) 2 (x, y) 4. Synthetic Aperture Radar SAR [4] [5], [6] Ground UWB · · FBTS SEABED 1 grid model boundary points model 3 1 Table 1 Characteristics of parametric and a non- parametric algorithms. Grid Model Boundary Points Model 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7

Sato, Toru

127

Radiated Emission of Breath Monitoring System Based on UWB Pulses in Spacecraft Modules  

NASA Astrophysics Data System (ADS)

The paper describes some EMC aspects related to a UWB radar for monitoring astronauts breathing activity. Compliance to EMC space standards forces some design aspects, in particular the peak voltage and the pulse waveform. Moreover some simulations were carried out to consider realistic operating condition. In the first case the interference towards a victim wifi circuit was analyzed, in the second case the effect of the environment on the radiated pulse was studied.

Russo, P.; Mariani Primiani, V.; De Leo, A.; Cerri, G.

2012-05-01

128

A Comparative Study of Wireless Protocols: Bluetooth, UWB, ZigBee, and Wi-Fi  

Microsoft Academic Search

Bluetooth (over IEEE 802.15.1), ultra-wideband (UWB, over IEEE 802.15.3), ZigBee (over IEEE 802.15.4), and Wi-Fi (over IEEE 802.11) are four protocol standards for short- range wireless communications with low power consumption. From an application point of view, bluetooth is intended for a cordless mouse, keyboard, and hands-free headset, UWB is oriented to high-bandwidth multimedia links, ZigBee is designed for reliable

Jin-Shyan Lee; Yu-Wei Su; Chung-Chou Shen

2007-01-01

129

Improved data model of TR-UWB system using multichannel autocorrelation receivers under NBI  

Microsoft Academic Search

Transmitted reference Ultra-wideband (TR-UWB) system in conjunction with autocorrelation receivers (AcR) is a popular low cost and low complexity radio system for low and mid-data rate applications. The scheme is in general robust against multipath fading. At the receiver front-end, however, both the desired UWB signal and narrowband interference (NBI) can enter to the radio receiver in which case several

Yohannes D. Alemseged; Klaus Witrisal; Hiroshi Harada

2009-01-01

130

High-order UWB pulses scheme to generate multilevel modulation formats based on incoherent optical sources.  

PubMed

We present a high-order UWB pulses generator based on a microwave photonic filter which provides a set of positive and negative samples by using the slicing of an incoherent optical source and the phase inversion in a Mach-Zehnder modulator. The simple scalability and high reconfigurability of the system permit a better accomplishment of the FCC requirements. Moreover, the proposed scheme permits an easy adaptation to pulse amplitude modulation, bi phase modulation, pulse shape modulation and pulse position modulation. The flexibility of the scheme for being adaptable to multilevel modulation formats permits to increase the transmission bit rate by using hybrid modulation formats. PMID:24514405

Bolea, Mario; Mora, José; Ortega, Beatriz; Capmany, José

2013-11-18

131

Ultra-wideband optical leaky-wave slot antennas.  

PubMed

We propose and investigate an ultra-wideband leaky-wave antenna that operates at optical frequencies for the purpose of efficient energy coupling between localized nanoscale optical circuits and the far-field. The antenna consists of an optically narrow aluminum slot on a silicon substrate. We analyze its far-field radiation pattern in the spectral region centered around 1550 nm with a 50% bandwidth ranging from 2000 nm to 1200 nm. This plasmonic leaky-wave slot produces a maximum far-field radiation angle at 32° and a 3 dB beamwidth of 24° at its center wavelength. The radiation pattern is preserved within the 50% bandwidth suffering only insignificant changes in both the radiation angle and the beamwidth. This wide-band performance is quite unique when compared to other optical antenna designs. Furthermore, the antenna effective length for radiating 90% and 99.9% of the input power is only 0.5?(0) and 1.5?(0) respectively at 1550 nm. The versatility and simplicity of the proposed design along with its small footprint makes it extremely attractive for integration with nano-optical components using existing technologies. PMID:21716477

Wang, Yan; Helmy, Amr S; Eleftheriades, George V

2011-06-20

132

Studies of scattering, reflectivity, and transmitivity in WBAN channel: feasibility of using UWB.  

PubMed

The Wireless Personal Area Network (WPAN) is one of the fledging paradigms that the next generation of wireless systems is sprouting towards. Among them, a more specific category is the Wireless Body Area Network (WBAN) used for health monitoring. On the other hand, Ultra-Wideband (UWB) comes with a number of desirable features at the physical layer for wireless communications. One big challenge in adoption of UWB in WBAN is the fact that signals get attenuated exponentially. Due to the intrinsic structural complexity in human body, electromagnetic waves show a profound variation during propagation through it. The reflection and transmission coefficients of human body are highly dependent upon the dielectric constants as well as upon the frequency. The difference in structural materials such as fat, muscles and blood essentially makes electromagnetic wave attenuation to be different along the way. Thus, a complete characterization of body channel is a challenging task. The connection between attenuation and frequency of the signal makes the investigation of UWB in WBAN an interesting proposition. In this paper, we study analytically the impact of body channels on electromagnetic signal propagation with reference to UWB. In the process, scattering, reflectivity and transmitivity have been addressed with analysis of approximate layer-wise modeling, and with numerical depictions. Pulses with Gaussian profile have been employed in our analysis. It shows that, under reasonable practical approximations, the human body channel can be modeled in layers so as to have the effects of total reflections or total transmissions in certain frequency bands. This could help decide such design issues as antenna characteristics of implant devices for WBAN employing UWB. PMID:22219673

Kabir, Md Humaun; Ashrafuzzaman, Kazi; Chowdhury, M Sanaullah; Kwak, Kyung Sup

2010-01-01

133

On UWB beamforming  

NASA Astrophysics Data System (ADS)

Ultra-Wideband (UWB) communication systems and Multi-Input-Multi-Output (MIMO) techniques rank among the few emerging key technologies in wireless communications. For that reason the marriage of these two complementary approaches should deserve attention. Apparently, the extremely large ultra-wide bandwidth creates rich multipath diversity which calls, at a first glance, additional antenna elements into question. However, another point of view is as follows. The attenuation by solid materials usually increases with increasing frequency; e.g. frequencies above, say, 10 GHz are considered to be blocked by walls etc. Since UWB can occupy more than 7 GHz of bandwidth (according to FCC regularisation) the performance of a communication link can be physically extended only by adding spatial information, i.e. multiple antennas, even if such extension may play a minor role. From this point of view UWB& MIMO presents an upper physical bound for indoor communications and is therefore at least worth to be investigated. In order to see the forest for the trees, we will focus in this limited contribution on beamforming among all alternative MIMO techniques (like space time coding or spatial multiplexing).

Kaiser, T.

2004-05-01

134

Group Delay in THz Spectroscopy with Ultra-Wideband Log-Spiral Antennae  

NASA Astrophysics Data System (ADS)

We report on the group delay observed in continuous-wave terahertz spectroscopy based on photomixing with phase-sensitive homodyne detection. We discuss the different contributions of the experimental setup to the phase difference ? ?( ?) between transmitter arm and receiver arm. A simple model based on three contributions yields a quantitative description of the overall behavior of ? ?( ?). Firstly, the optical path-length difference gives rise to a term linear in frequency ?. Secondly, the ultra-wideband log-spiral antennae effectively radiate and receive in a frequency-dependent active region, which in the most simple model is an annular area with a circumference equal to the wavelength. The corresponding term changes by roughly 6 ? between 100 GHz and 1 THz. The third contribution stems from the photomixer impedance. In contrast, the derivative ?? ?/ ? ? is dominated by the contribution of periodic modulations of ? ?( ?) caused by standing waves, e.g., in the photomixers' Si lenses. Furthermore, we discuss the Fourier-transformed spectra, which are equivalent to the waveform in a time-domain experiment. In the time domain, the group delay introduced by the log-spiral antennae gives rise to strongly chirped signals, in which low frequencies are delayed. Correcting for the contributions of antennae and photomixers yields sharp peaks or "pulses" and thus facilitates a time-domain-like analysis of our continuous-wave data.

Langenbach, M.; Roggenbuck, A.; Cámara Mayorga, I.; Deninger, A.; Thirunavukkuarasu, K.; Hemberger, J.; Grüninger, M.

2014-11-01

135

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

136

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

137

Fingerprinting Localization based on Neural Networks and Ultra-wideband signals  

E-print Network

Fingerprinting Localization based on Neural Networks and Ultra-wideband signals Lei Yu, Mohamed Abstract--Fingerprinting techniques have been proved as an effective techniques for determining (RSS) are subject to big positioning errors. In this paper, a fingerprinting based localization

Paris-Sud XI, Université de

138

Ultra wideband digital to analog conversion based on advanced InP DHBT technology  

Microsoft Academic Search

Wideband digital-to-analog converters (DACs) are key to future high performance military electronic systems. This paper presents the results of an ultra wideband DAC based on advanced InP DHBT technology. The chip integrates a 40-to-10 bit digital multiplexer with a 10-bit DAC and associated clock generation.

D. Ching; K. Tsai; A. Gutierrez; B. Oyama

2005-01-01

139

ORAL PRESENTATION ABSTRACT Antenna Array Design for Ultra-wideband Microwave Detection of Breast Cancer Tumours  

E-print Network

ORAL PRESENTATION ABSTRACT Antenna Array Design for Ultra-wideband Microwave Detection of Breast Cancer Tumours by Alistair Johnson Electrical and Biomedical Engineering It has been reported in literature that cancerous tissue in the breast exhibits separate dielectric properties than normal breast

Haykin, Simon

140

CPW-Fed Quasi-Magnetic Printed Antenna for Ultra-Wideband Applications  

Microsoft Academic Search

An optimized coplanar waveguide fed quasimagnetic printed antenna for ultra wideband applications is described. A parameter study, motivated by a design procedure, allowed a substantial increase in the return-loss operational bandwidth. The numerically predicted performance was validated by means of physical measurements of fabricated samples. The measured radiation patterns of the antenna demonstrated its adequate radiation characteristics. The feed radiation

F. Muge Tanyer-Tigrek; Dani P. Tran; I. E. Lager; Leonardus P. Ligthart

2009-01-01

141

Considerations for source pulses and antennas in UWB radio systems  

Microsoft Academic Search

This paper addresses two vital design considerations in ultrawide-band radio systems. One is that radiated power density spectrum shaping must comply with certain emission limit mask for coexistence with other electronic systems. Another is that the design of source pulses and transmitting\\/receiving antennas should be optimal for the performance of overall systems. The design of source pulses and transmitting\\/receiving antennas

Zhi Ning Chen; Xuan Hui Wu; Hui Feng Li; Ning Yang; M. Y. W. Chia

2004-01-01

142

UWB 3.1–10.6 GHz CMOS transmitter for system-on-a-chip nano-power pulse radars  

Microsoft Academic Search

The building blocks of the transmitter for system-on-a-chip CMOS nano-power radar systems are presented. They consist of a novel fully integrated UWB pulse generator and a digitally programmable delay element. The pulse generator provides monocycle pulses with duration time close to 250 ps and 1-V peak-to-peak amplitude. In detail, the circuit provides a sinusoidal-like monocycle when activated by a negative

Fabio Zito; Domenico Zito; Domenico Pepe

2007-01-01

143

Millimeter-wave silicon-based ultra-wideband automotive radar transceivers  

NASA Astrophysics Data System (ADS)

Since the invention of the integrated circuit, the semiconductor industry has revolutionized the world in ways no one had ever anticipated. With the advent of silicon technologies, consumer electronics became light-weight and affordable and paved the way for an Information-Communication-Entertainment age. While silicon almost completely replaced compound semiconductors from these markets, it has been unable to compete in areas with more stringent requirements due to technology limitations. One of these areas is automotive radar sensors, which will enable next-generation collision-warning systems in automobiles. A low-cost implementation is absolutely essential for widespread use of these systems, which leads us to the subject of this dissertation---silicon-based solutions for automotive radars. This dissertation presents architectures and design techniques for mm-wave automotive radar transceivers. Several fully-integrated transceivers and receivers operating at 22-29 GHz and 77-81 GHz are demonstrated in both CMOS and SiGe BiCMOS technologies. Excellent performance is achieved indicating the suitability of silicon technologies for automotive radar sensors. The first CMOS 22-29-GHz pulse-radar receiver front-end for ultra-wideband radars is presented. The chip includes a low noise amplifier, I/Q mixers, quadrature voltage-controlled oscillators, pulse formers and variable-gain amplifiers. Fabricated in 0.18-mum CMOS, the receiver achieves a conversion gain of 35-38.1 dB and a noise figure of 5.5-7.4 dB. Integration of multi-mode multi-band transceivers on a single chip will enable next-generation low-cost automotive radar sensors. Two highly-integrated silicon ICs are designed in a 0.18-mum BiCMOS technology. These designs are also the first reported demonstrations of mm-wave circuits with high-speed digital circuits on the same chip. The first mm-wave dual-band frequency synthesizer and transceiver, operating in the 24-GHz and 77-GHz bands, are demonstrated. All circuits except the oscillators are shared between the two bands. A multi-functional injection-locked circuit is used after the oscillators to reconfigure the division ratio inside the phase-locked loop. The synthesizer is suitable for integration in automotive radar transceivers and heterodyne receivers for 94-GHz imaging applications. The transceiver chip includes a dual-band low noise amplifier, a shared downconversion chain, dual-band pulse formers, power amplifiers, a dual-band frequency synthesizer and a high-speed programmable baseband pulse generator. Radar functionality is demonstrated using loopback measurements.

Jain, Vipul

144

Short-Range Ultra-Wideband Systems UMass Antenna Lab USC UltRa Lab UC Berkeley BWRC  

E-print Network

matching using active negative inductance elements · Modeling of multipath propagation Dave Pozar #12;Short of radius a mathematical sphere of radius a Dave Pozar #12;Short-Range Ultra-Wideband Systems UMass Antenna

Southern California, University of

145

Analysis of Channel-Averaged SINR for Indoor UWB Rake and Transmitted Reference Systems  

Microsoft Academic Search

In this paper, we derive a closed-form expression for channel-averaged signal-to-interference-plus-noise ratio (SINR) for ultra-wideband (UWB) Rake receiving system in an indoor multiuser communication scenario, given that the interference level is fluctuating due to asynchronous transmissions among users. The indoor wireless channel model adopted here is a standard one, recently released by IEEE 802.15 study group 3a . We propose

Tao Jia; Dong In Kim

2007-01-01

146

A 90-nm CMOS LNA for MB-OFDM UWB in QFN package  

Microsoft Academic Search

In this work, the design of a single ended low-noise amplifier (LNA) dedicated for multi-band orthogonal frequency-division multiplexing (MB-OFDM) Band Group-1 ultra-wideband (UWB) band is described. It achieves a flat gain from 2 to 5 GHz of 17 dB while drawing a current of 15.9 mA from a 1.2 V supply. The circuit has been implemented in 90 -nm CMOS

King Wah Wong; M. Annamalai Arasu; Wei Khuen Chan

2008-01-01

147

Modeling and Mitigation of Narrowband Interference for Transmitted-Reference UWB Systems  

Microsoft Academic Search

Transmitted-reference ultra-wideband (TR-UWB) systems, in conjunction with autocorrelation-receivers (AcR), can collect all energy of the multipath channel response at low complexity. Unfortunately the AcR front-end also collects the energy of narrowband interference (NBI) signals, which severely degrades its performance. We present an elaborate statistical analysis of the NBI for a multichannel AcR front-end. Our results show specific correlation properties, which

Yohannes D. Alemseged; Klaus Witrisal

2007-01-01

148

The effects of antenna directivity on path loss and multipath propagation in UWB indoor wireless channels  

Microsoft Academic Search

The effects of antenna directivity on path loss and multipath propagation in the ultra-wideband (UWB) indoor channel are analyzed for different transmitter\\/receiver (Tx\\/Rx) antenna combinations in the 2 GHz to 6 GHz frequency band. A statistical model of the path loss in the channel is presented, where the parameters in the model (i.e., path loss exponent and shadow fading statistics)

Jason A. Dabin; Nan Ni; Alexander M. Haimovich; Edip Niver; Haim Grebel

2003-01-01

149

1-cc computer using UWB-IR for wireless sensor network  

Microsoft Academic Search

An ultra-small, high-data-rate, low-power 1-cc computer (OCCC) with an UWB-IR (ultra-wideband impulse-radio) transceiver was developed for a wireless sensor network. Thanks to bear-chip implementation and a flexible printed circuit board, the size of the computer is only 1 cm3. To achieve 10-Mbps data rate, a middle-class 32-bit microcontroller, which has both a bus interface and a USB 2.0 controller, was

Tatsuo Nakagawa; Masayuki Miyazaki; Goichi Ono; Ryosuke Fujiwara; Takayasu Norimatsu; Takahide Terada; Akira Maeki; Yuji Ogata; Shinsuke Kobayashi; Noboru Koshizuka; Ken Sakamura

2008-01-01

150

1-cc Computer: Cross-Layer Integration With UWB-IR Communication and Locationing  

Microsoft Academic Search

The first one-cc or one-cubic-centimeter computer (OCCC) that integrates a sensor, ultra-wideband impulse radio (UWB-IR) transmitter, computing engine, and battery is demonstrated. Cross-layer integration includes SPIKE control, which achieves a record low power communication of 3.4-nW\\/bps with reduced operating time. Miniaturization techniques, such as wafer-level chip-size packaging and flip-chip packaging, were used to shrink the module to a volume of

Tatsuo Nakagawa; Goichi Ono; Ryosuke Fujiwara; Takayasu Norimatsu; Takahide Terada; Masayuki Miyazaki; Kei Suzuki; Kazuo Yano; Yuji Ogata; Akira Maeki; Shinsuke Kobayashi; Noboru Koshizuka; Ken Sakamura

2008-01-01

151

On the Evaluation of Channel Capacity of UWB Indoor Wireless Systems  

Microsoft Academic Search

This paper discusses the channel capacity of multiantenna ultra-wideband (UWB) indoor wireless systems. It is shown first that for both single-input single-output (SISO) and multiple-input multiple-output (MIMO) cases, when the transmit SNR is lower than some value, say -20 dB, using optimal power spectrum allocation (OPSA) at the transmitter side can increase the reliable transmission rate considerably compared to the

Feng Zheng; Thomas Kaiser

2008-01-01

152

A 3.1-10.6 GHz 100 Mb/s Chipset for Pulsed-UWB Fred S. Lee, Nathan Ackerman, Manish Bhardwaj, Raul Blazquez, Christian R. Deonier,  

E-print Network

A 3.1-10.6 GHz 100 Mb/s Chipset for Pulsed-UWB Fred S. Lee, Nathan Ackerman, Manish Bhardwaj, Raul Blazquez, Christian R. Deonier, Brian P. Ginsburg, Johnna Powell, Vivienne Sze, David D. Wentzloff, Anantha

Southern California, University of

153

Accurate TOA-Based UWB Localization System in Coal Mine Based on WSN  

NASA Astrophysics Data System (ADS)

Over the last years, there has been a great deal of interest in Ultra Wideband (UWB) wireless communication and Wireless Sensor Networks(WSN), especially following the proposing of the internet of things by the MIT (Massachusetts Institute of Technology) in 1999, hich is also result in an increasing research on UWB and WSN applications. This article mainly introduced the accurate UWB Localization System based on WSN in coal mine. Firstly, we briefly introduced UWB and WSN Localization technology. Secondly, the advantages and disadvantages of the previous personnel localization technology in coal mine was analyzed and contrasted, and then the suitable personnel localization system in coal mine based on UWB signal and TOA estimate positioning scheme are presented. At last the rationality and feasibility of this scheme was proved through the simulation results.

Cheng, Guangliang

154

A 255 MHz Programmable Gain Amplifier and Low-Pass Filter for Ultra Low Power Impulse-Radio UWB Receivers  

Microsoft Academic Search

A 90 nm-CMOS power-optimized analog baseband chain for ultra-low-power impulse-radio ultra-wideband (IR-UWB) receivers is presented. The proposed device merges the functions of a programmable gain amplifier (PGA) and a low-pass filter (LPF). It consists of the cascade of three biquadratic cells made up by opamps in a series-shunt configuration, which features high input impedance, low load effects in the cascade

Stefano D'Amico; Marco De Blasi; Marcello De Matteis; Andrea Baschirotto

2012-01-01

155

An iterative procedure for ultra-wideband imagery of space objects from distributed multi-band radar data  

NASA Astrophysics Data System (ADS)

A novel technique is proposed for ultra-wideband imagery of space objects from distributed multi-band radar data. The complex exponential (CE) model is used for representation of ultra-wideband radar signals, where an iterative procedure is developed for optimized model parameter estimation. A subband coherent processing technique is developed which combines the de-noising cross-correlation (DNCC) algorithm with statistical method to obtain the phase and amplitude incoherent parameters (ICP) between subbands. Ultra-wideband data fusion via two-dimensional gapped-data state space approach (2-D GSSA) is then applied to multiple subband signals for supper-resolution imagery. Experiments using computational electromagnetic data from the method of moment (MoM) as well as anechoic chamber measurement data are used to validate the proposed technique and demonstrate its applications.

Xu, Xiaojian; He, Feiyang

2014-09-01

156

Photonic generation of UWB impulses by using a Fabry-Pérot semiconductor optical amplifier  

NASA Astrophysics Data System (ADS)

A novel approach to generating ultra-wideband (UWB) impulses based on a Mach-Zehnder modulator (MZM) and a Fabry-Pérot semiconductor optical amplifier (FP-SOA) is proposed and demonstrated. Both the carrier dynamic behavior of SOA and the feedback of FP cavity are exploited to generate a pair of polarity-reversed doublet-like impulses. Simulations and experiments are carried out to verify the UWB generation. In the experiment, the fractional bandwidths of the negative-doublet-like and the positive-doublet-like impulses are 100% and 108%, respectively. The bit error rate (BER) performance of the UWB before and after a span of 19-km standard single mode fiber (SSMF) transmission is also investigated and error-free performance can be achieved for each condition. Finally the UWB wireless transmission over a span of 10 cm is investigated.

Yu, Yuan; Dong, Jianji; Jiang, Fan; Luo, Bowen; Zhang, Xinliang

2014-03-01

157

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

158

Reception and processing of electromagnetic pulses after propagation through dispersive and dissipative media  

Microsoft Academic Search

Ultra-wideband (UWB) ground penetrating radar (GPR) systems are useful for extracting and displaying information for target recognition purposes. The frequency content of projected signals is designed to match the size and type of prospective targets and environments. The soil medium is generally dispersive and, if moist, dissipative as well. Hence, target signatures whether in the time, frequency or joint time-frequency

H. C. Strifors; Guillermo C. Gaunaurd; Anders Sullivan

2003-01-01

159

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 54, NO. 5, SEPTEMBER 2005 1623 An Ultra-Wideband Transceiver Architecture for Low  

E-print Network

Terms--Digital radio, impulse radio, low power, transceiver, ultra-wideband. I. INTRODUCTION approaches due to the wideband, i.e., low-Q, nature of the radio. The anticipated power savings, over-Wideband Transceiver Architecture for Low Power, Low Rate, Wireless Systems Ian D. O'Donnell, Member, IEEE, and Robert

Southern California, University of

160

Detection of target scattering centers in terrain clutter using an ultra-wideband, fully-polarimetric synthetic aperture radar  

Microsoft Academic Search

We study the processing of full-polarization data collected by an ultra-wideband synthetic aperture radar in order to detect targets embedded in terrain clutter. We focus on the use of polarization diversity in a high resolution application to incorporate partial knowledge of the target into the detector design and to model geometrically relevant unknown parameters. We consider a family of generalized

Ronald Louis Dilsavor

1993-01-01

161

Detection of Physics-based Ultra-wideband Signals Using Generalized RAKE in Presence of Inter-Symbol Interference  

E-print Network

Detection of Physics-based Ultra-wideband Signals Using Generalized RAKE in Presence of Inter-Symbol Interference John Qiang Zhang and Robert Caiming Qiu Abstract-- The generalized rake receiver based on physics rate. Index Terms-- Generalized rake receiver, Physics-based channel, Successive channel estimation

Qiu, Robert Caiming

162

Hardware Aware Optimization of an Ultra Low Power UWB Communication System  

Microsoft Academic Search

A wireless body area network with an average throughput of 500 kbps based on ultra-wideband pulse position modulation is considered. For a long battery autonomy a hardware aware system optimization with respect to the specific applications at hand is essential. A key feature to achieve power savings is low duty cycle signaling, and its effectiveness when combined with burst-wise transmission

Florian Troesch; Christoph Steiner; Thomas Zasowski; Thomas Burger; Armin Wittneben

2007-01-01

163

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

164

Design and performance of an ultra-wideband stepped-frequency radar with precise frequency control for landmine and IED detection  

NASA Astrophysics Data System (ADS)

The Army Research Laboratory (ARL) has developed an impulse-based vehicle-mounted forward-looking ultra- wideband (UWB) radar for imaging buried landmines and improvised explosive devices (IEDs). However, there is no control of the radiated spectrum in this system. As part of ARL's Partnerships in Research Transition (PIRT) program, the above deficiency is addressed by the design of a Stepped-Frequency Radar (SFR) which allows for precise control over the radiated spectrum, while still maintaining an effective ultra-wide bandwidth. The SFR utilizes a frequency synthesizer which can be configured to excise prohibited and interfering frequency bands and also implement frequency-hopping capabilities. The SFR is designed to be a forward-looking ground- penetrating (FLGPR) Radar utilizing a uniform linear array of sixteen (16) Vivaldi notch receive antennas and two (2) Quad-ridge horn transmit antennas. While a preliminary SFR consisting of four (4) receive channels has been designed, this paper describes major improvements to the system, and an analysis of expected system performance. The 4-channel system will be used to validate the SFR design which will eventually be augmented in to the full 16-channel system. The SFR has an operating frequency band which ranges from 300 - 2000 MHz, and a minimum frequency step-size of 1 MHz. The radar system is capable of illuminating range swaths that have maximum extents of 30 to 150 meters (programmable). The transmitter has the ability to produce approximately -2 dBm/MHz average power over the entire operating frequency range. The SFR will be used to determine the practicality of detecting and classifying buried and concealed landmines and IEDs from safe stand-off distances.

Phelan, Brian R.; Sherbondy, Kelly D.; Ranney, Kenneth I.; Narayanan, Ram M.

2014-05-01

165

An ultra-wideband transmit/receive module using 10 to 35 GHz six-channel microstrip multiplexers and its applications to phased-array antenna transceiver systems  

E-print Network

developed. Recent advances in broadband monolithic microwave integrated circuit (MMIC) amplifiers make the realization of extremely broadband phased-array transceiver systems possible. The ultra-wideband phased-array transceiver systems can be used in multi...

Hong, Seung Pyo

2006-10-30

166

A statistical ultra-wideband indoor channel model and the effects of antenna directivity on path loss and multipath propagation  

Microsoft Academic Search

Ultra-wideband indoor line-of-sight frequency-domain channel measurements have been performed in the 2-6 GHz frequency band using three different transmit\\/receive antenna combination pairs. The effects of antenna directivity on path loss and multipath propagation in the channel are analyzed extensively for various omnidirectional and directional antenna combinations. A statistical model of the path loss in the channel is presented, in which

Jason A. Dabin; Alexander M. Haimovich; Haim Grebel

2006-01-01

167

An ultra-wideband printed monopole antenna with the gain enhanced using a surface-mounted short horn  

Microsoft Academic Search

An ultra-wideband printed monopole antenna, improved by attaching a short two-plate horn to its surface, is reported in this paper. The short horn, which has a slant length of 45 mm and a total physical height of 46.9 mm, significantly increases the gain of the printed monopole antenna at lower frequencies where the gain of the monopole is otherwise low,

Y. Ranga; Karu P. Esselle; A. R. Weily; A. K. Verma

2010-01-01

168

Design of CMOS integrated frequency synthesizers for ultra-wideband wireless communications systems  

E-print Network

Ultra¬wide band (UWB) system is a breakthrough in wireless communication, as it provides data rate one order higher than existing ones. This dissertation focuses on the design of CMOS integrated frequency synthesizer and its building blocks used...

Tong, Haitao

2009-05-15

169

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

170

Zpectrometer: an Ultra-wideband Spectrometer for Redshift Searches with the Green Bank Telescope  

NASA Astrophysics Data System (ADS)

To understand the cosmic histories of star formation and accretion, observers must determine the redshifts of distant galaxies whose central starbursts and/or active nuclei are heavily obscured by dust. Direct spectroscopy of molecular emission lines is the ideal way to meet this challenge, but a suitable instrument must have large instantaneous bandwidth to achieve broad redshift coverage. We describe a new, ultra-wideband "Zpectrometer" now under construction for the Green Bank Telescope that satisfies this need. Using a novel analog lag cross-correlator spectrometer technology in a correlation radiometer architecture, the Zpectrometer will produce stable spectra over the entire 26-40 GHz range of the GBT's Ka-band receiver. The Zpectrometer will enable blind searches for CO(1-0) emission in the redshift range where the cosmic star formation rate density peaks, higher-J CO transitions at earlier epochs, and rotational lines from other molecules at a variety of redshifts. This project is funded by a National Science Foundation ATI Program grant to the University of Maryland and by contributions from the National Radio Astronomy Observatory.

Baker, A. J.; Harris, A. I.; Jewell, P. R.; Rauch, K. P.; Zonak, S. G.; O'Neil, K.; Shelton, A. L.; Norrod, R. D.; Ray, J.; Watts, G.

2005-12-01

171

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

172

Statistical Analysis of UWB Channel Correlation Functions  

Microsoft Academic Search

Various performance metrics of impulse-radio (IR) ultrawideband (UWB) receivers are closely connected to the correlation functions of the multipath channel responses to UWB pulses. Interpulse interference is related to the autocorrelation function (ACF) of the received pulse (RP), the RP energy and its fading correspond to the ACF at zero lag, and multiple access interference is connected to the cross-correlation

Klaus Witrisal; Marco Pausini

2008-01-01

173

An all-digital transmitter for pulsed ultra-wideband communication  

E-print Network

Applications like sensor networks, medical monitoring, and asset tracking have led to a demand for energy-efficient and low-cost wireless transceivers. These types of applications typically require low effective data rates, ...

Mercier, Patrick Philip

2008-01-01

174

Provision of IR-UWB wireless and baseband wired services over a WDM-PON.  

PubMed

A simple scheme to simultaneously generate an on-off keying or bi-phase modulation (BPM) impulse radio ultra wideband (IR-UWB) signal and a baseband wired signal in the optical domain using a dual-drive modulator is proposed and demonstrated. Although the two signals have spectral overlap in the optical spectrum, they are located at different frequency bands when converted to electrical signals at a photodetector (PD), which can be well separated by an electrical filter. An experiment is carried out. Eye diagrams, electrical spectra and BER measurements show that the co-channel interference between the UWB and the wired signals is small for a single-channel 36-km fiber link to provide 1.25-Gb/s UWB wireless and 1.25-Gb/s baseband wired services. The inter-channel interference is also small and negligible when the link is operated together with two other 1.25 Gb/s baseband wired links, which demonstrates that a conventional WDM-PON can be upgraded to provide additional UWB services without affecting the existing services by modifying the modulators in the center office and inserting UWB antennas in the optical network units. PMID:22274021

Pan, Shilong; Yao, Jianping

2011-12-12

175

Ultra-Wideband, Low-Power, Inductorless, 3.1–4.8 GHz, CMOS VCO  

Microsoft Academic Search

A low-power, inductorless, UWB CMOS voltage controlled oscillator is designed in 0.18 ?m CMOS technology targeting to a UWBFM\\u000a transmitter application. The VCO is a Double-Cross-Coupled Multivibrator and generates output frequencies ranging from 1.55 GHz\\u000a to 2.4 GHz. A low-power frequency doubler based on a Gilbert cell, which operates in weak inversion, doubles the VCO tuning\\u000a range from 3.1 GHz to 4.8 GHz. The proportionality between

Athanasios Tsitouras; Fotis Plessas

2011-01-01

176

Short-Range Ultra-Wideband Systems UMass Antenna Lab USC UltRa Lab UC Berkeley BWRC  

E-print Network

directions that may be interesting UWB Antenna Theory and Design David Pozar Electrical and Computer. Pozar, "Closed-form approximations for link loss in an UWB radio system using small antennas", IEEE waveforms implemented by using 4-bit quantization result in reasonably good link performance. D. M. Pozar

Southern California, University of

177

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

178

Sample selection and adaptive weight allocation for compressive MIMO UWB noise radar  

NASA Astrophysics Data System (ADS)

In this paper, we propose a sample selection method for compressive multiple-input multiple-output (MIMO) ultra-wideband (UWB) noise radar imaging. The proposed sample selection is based on comparing norm values of the transmitted sequences, and selects the largest M samples among N candidates per antenna. Moreover, we propose an adaptive weight allocation which improves normalized mean-square error (NMSE) by maximizing the mutual information between target echoes and the transmitted signals. Further, this weighting scheme is applicable to both sample selection schemes, a conventional random sampling and the proposed selection. Simulations show that the proposed selection method can improve the multiple target detection probability and NMSE. Moreover, the proposed weight allocation scheme is applicable to those selection methods and obtains spatial diversity and signal-to-noise ratio (SNR) gains.

Kwon, Yangsoo; Narayanan, Ram M.; Rangaswamy, Muralidhar

2012-06-01

179

IEEE TRANSACTIONS ON ADVANCED PACKAGING, VOL. 30, NO. 3, AUGUST 2007 533 Design and Fabrication of Ultra-Wideband  

E-print Network

(LCP) flex. Fabrication techniques are demonstrated for processing these commercially available LCP thin-films by standard PCB equipments. Variations in the LCP thin-film thickness are characterized imbalance less than 1.2 dB and 2 , respectively. These baluns are ideal for applications in UWB

Pham, Anh-Vu

180

Design of a 3.1-4.8 GHZ RF front-end for an ultra wideband receiver  

E-print Network

frequency band of 3.168 GHz ? 10.6 GHz is an emerging solution to this with data rates of 110, 200 and 480 Mbps. Initially, UWB mode I devices using only 3.168 GHz ? 4.752 GHz have been proposed. Low Noise Amplifier (LNA) and I-Q mixers are key components...

Sharma, Pushkar

2006-08-16

181

A 0.25-?m CMOS Low-Power UpConversion Mixer for 3.1-5 GHz Ultra-Wideband Applications  

Microsoft Academic Search

This paper presents a low-power up-conversion mixer, designed in a standard 0.25-mum CMOS technology, for 3.1-5 GHz ultra-wideband applications. The circuit provides 3.8 dB of power gain and an output-referred 1-dB compression point of -14.7 dBm, while drawing only 1.3 mA from a 1.5-V supply voltage. The 3-dB frequency bandwidth is 1.9 GHz, from 3.1 GHz to 5 GHz, and

G. Sapone; G. Palmisano

2006-01-01

182

High-Chip-Count UWB Biphase Coding for Multiuser UWB-Over-Fiber System  

Microsoft Academic Search

In this paper, we propose and demonstrate a novel technique to optically generate high-chip-count, phase-coded direct-sequence (DS) ultrawideband (UWB) signals for multiple-access UWB communications. In the proposed system, a lightwave from a laser source is phase-modulated by a Gaussian pulse train. The phase-modulated lightwave is then sent to a polarization modulator, to modulate the polarization state of the lightwave by

Yitang Dai; Jianping Yao

2009-01-01

183

Reconfigurable UWB Bandpass Filter with Flexible Notch Characteristics  

NASA Astrophysics Data System (ADS)

The thesis reports a compact tunable ultra-wideband (UWB) notch filter using hybrid microstrip and coplanar waveguide (CPW) structure. The tunable notch is implemented to filter out the wireless local area network (WLAN) channels from 5GHz to 6GHz. The proposed structure utilizes the resonance of open ended stubs to achieve transmission zeroes in the filter passband. Varactors and by-pass capacitors are then introduced for dynamic tunability of notch. Further, the electromagnetic decoupling of the two resonators leads to tunable bandwidth of notch. DC bias circuitry is implemented to control the varactor capacitances. Rejection levels up to 25 dB are attained using this technique while maintaining insertion loss levels below 2.5 dB in the passband. The reconfigurability of bandwidth is shown by maintaining a constant bandwidth of 150 MHz across the WLAN band for the notch. The filter achieves an excellent wide bandwidth (from 2.5 GHz to 8.5 GHz) using multimode-resonator (MMR) based topology which makes the filter one wavelength long at the central frequency.

Dhwaj, Kirti

184

A progressive processing method for breast cancer detection via UWB based on an MRI-derived model  

NASA Astrophysics Data System (ADS)

Ultra-wideband (UWB) microwave imaging is a promising method for breast cancer detection based on the large contrast of electric parameters between the malignant tumor and its surrounded normal breast organisms. In the case of multiple tumors being present, the conventional imaging approaches may be ineffective to detect all the tumors clearly. In this paper, a progressive processing method is proposed for detecting more than one tumor. The method is divided into three stages: primary detection, refocusing and image optimization. To test the feasibility of the approach, a numerical breast model is developed based on the realistic magnetic resonance image (MRI). Two tumors are assumed embedded in different positions. Successful detection of a 3.6 mm-diameter tumor at a depth of 42 mm is achieved. The correct information of both tumors is shown in the reconstructed image, suggesting that the progressive processing method is promising for multi-tumor detection.

Xiao, Xia; Song, Hang; Wang, Zong-Jie; Wang, Liang

2014-07-01

185

Path loss and matched filter gain of free space and ground reflection channels for UWB radio systems  

Microsoft Academic Search

In this paper, the path loss and matched filter gain of free space and ground reflection channels for UWB radio systems are proposed. The passband rectangular pulse with specific center frequency and bandwidth is used as the transmitted signal. The complex form Friis' transmission formula is used for the UWB channel. The received signal is evaluated. The UWB path loss

S. Promwong; J. Takada; P. Supanakoon; P. Tangtisanon

2004-01-01

186

Hybrid UWB and WiMAX radio-over-multi-mode fibre for in-building optical networks  

NASA Astrophysics Data System (ADS)

In this paper the use of hybrid WiMedia-defined ultra-wideband (UWB) and IEEE 802.16d WiMAX radio-over-fibre is proposed and experimentally demonstrated for multi-mode based in-building optical networks with the advantage of great immunity to optical transmission impairments. In the proposed approach, spectral coexistence of both signals must be achieved with negligible mutual interference. The experimental study performed addressed an indoor configuration with 50 ?m multi-mode fibres (MMF) and 850 nm vertical-cavity surface-emitting laser (VCSEL) transmitters. The results indicate that the impact of the wireless convergence in radio-over-multi-mode fibre (RoMMF) is significant for UWB transmissions, mainly due to MMF dispersion and electrooptical (EO) devices with limited bandwidth. On the other hand, WiMAX transmission is feasible for a 300 m MMF and 30 m wireless link in the presence of UWB, with -31 dBm WiMAX EVM.

Perez, J.; Llorente, R.

2014-01-01

187

Low-power wide-locking-range injection-locked frequency divider for OFDM UWB systems  

NASA Astrophysics Data System (ADS)

This paper describes a divide-by-two injection-locked frequency divider (ILFD) for frequency synthesizers as used in multiband orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) systems. By means of dual-injection technique and other conventional tuning techniques, such as DCCA and varactor tuning, the divider demonstrates a wide locking range while consuming much less power. The chip was fabricated in the Jazz 0.18 ?m RF CMOS process. The measurement results show that the divider achieves a locking range of 4.85 GHz (6.23 to 11.08 GHz) at an input power of 8 dBm. The core circuit without the test buffer consumes only 3.7 mA from a 1.8 V power supply and has a die area of 0.38 × 0.28 mm2. The wide locking range combined with low power consumption makes the ILFD suitable for its application in UWB systems.

Jiangwei, Yin; Ning, Li; Renliang, Zheng; Wei, Li; Junyan, Ren

2009-05-01

188

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

189

Design of UWB Monopole Antenna with Dual Notched Bands Using One Modified Electromagnetic-Bandgap Structure  

PubMed Central

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

Xu, Ziqiang

2013-01-01

190

Subbanding of temporal and spatial UWB SAR imagery of buried mines  

NASA Astrophysics Data System (ADS)

A numerical algorithm has been developed for the modeling of ultra-wideband (UWB) plane-wave scattering from a class of buried mines. In particular, the model assumes that a mine can be simulated as a body of revolution (BOR). The numerical results indicate that there are particular frequency subbands in which a given target is excited most strongly, with the subband depending strongly on the target type. Moreover, these optimal subbands are also dependent on the depression angle; therefore, the synthetic aperture radar (SAR) aperture must be limited (spatial-spectrum subbanding) so that the desired depression angle is achieved over the aperture used for imaging. These results indicate that the scattered response from particular buried mines can be highlighted by proper processing of the temporal and spatial spectrum. So motivated, we have applied subbanding to data measured by the Army Research Laboratory (ARL) UWB SAR, which collects fully polarimetric data over the 50 - 1200 MHz bandwidth. The measured data, when processed appropriately corroborate the theoretical expectations of where example anti-personnel and anti-tank mines scatter optimally. In particular, we consider the Valmara anti-personnel mine and the M20 anti-tank mine, using data collected at Yuma Proving Grounds. After validating the theory, we present frequency subbanding that will highlight one mine over another, a technique of potential application to the discrimination of targets from clutter.

Wong, David C.; Carin, Lawrence

1998-09-01

191

Photonic generation multiband UWB impulse radio signal  

NASA Astrophysics Data System (ADS)

A novel method to photonic generation multiband ultra-wide band (MB-UWB) impulse radio signal based on the summation of multiple doublet pulses with different weights and proper time delays is proposed. Microwave sinusoidal signal is used to amplitude modulate a tunable laser to get multi-wavelength source. The optical signal is then phase modulation with Gaussian pulse and fed into a section of single-mode fiber (SMF). The SMF services as phase modulation to intensity modulation (PM-IM) conversion to generate Gaussian doublet pulse, and offers proper time delays to Gaussian doublet pulses with different weights. MB-UWB pulses with sidelobe suppression levels over 25 dB, central frequency from 5 to 8 GHz, 10 dB bandwidth from 2.9 to 3.8 GHz are obtained in experiment.

Sun, Guodan; Wang, Rong; Pu, Tao; Wei, Zhihu

2013-05-01

192

Launch device using endlessly single-mode PCF for ultra-wideband WDM transmission in graded-index multi-mode fiber.  

PubMed

We demonstrated ultra-wideband wavelength division multiplexing (WDM) transmission from 850 to 1550 nm in graded-index multi-mode fiber (GI-MMF) using endlessly single-mode photonic crystal fiber (ESM-PCF) as a launch device. Effective single-mode guidance is obtained in multi-mode fiber at all wavelengths by splicing cm-order length ESM-PCF to the transmission fiber. We achieved 3 × 10 Gbit/s WDM transmission in a 1 km-long 50-?m-core GI-MMF. We also realized penalty free 10 Gbit/s data transmission at a wavelength of 850 nm by optimizing the PCF structure. This method has the potential to achieve greater total transmission capacity for MMF systems by the addition of more wavelength channels. PMID:23187257

Ma, Lin; Hanzawa, Nobutomo; Tsujikawa, Kyozo; Azuma, Yuji

2012-10-22

193

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

E-print Network

chal- lenges which motivate our multiband approach. First, with impulse-based UWB, pulses are subjectMultiband Media Access Control in Impulse-Based UWB Ad Hoc Networks Ioannis Broustis, Student pulses in one of many narrower frequency bands. The motivation comes from the observation that

Krishnamurthy, Srikanth

194

Distributed Cooperative Data Transfer for UWB Adhoc Network  

Microsoft Academic Search

In this conference paper we address the problem of distributed cooperative data transfer for ultra wide band (UWB) ad-hoc networks: (1) we propose three improving techniques that can utilize some available but not-yet-utilized additional resources to improve the sub-optimal but widely adopted autocorrelation differential detection for the widely used pulse-based UWB data transfer; (2) we devise three cooperative transmission strategies,

Shouhong Zhu; Kin K. Leung; Anthony G. Constantinides

2007-01-01

195

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

196

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

197

A CPW-Fed Circular Wide-Slot UWB Antenna with Wide Tunable and Flexible Reconfigurable Dual Notch Bands  

PubMed Central

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

198

A framework for simulation of UWB system for heart rate detection  

Microsoft Academic Search

Ultra-Wide Band (UWB) signals have become attractive for their particular advantage of having narrow pulse width which makes them suitable for remote sensing of vital signals. In this work, a MATLAB framework is presented which simulates an environment whereby the UWB signals can be observed and evaluated at different locations of the simulated channel for wireless measurement of heart rate.

Mehran Baboli; Azadeh Sharafi; Alireza Ahmadian; Saeed KarimiFard

2009-01-01

199

A new wavelet based algorithm for estimating respiratory motion rate using UWB radar  

Microsoft Academic Search

UWB signals have become attractive for their particular advantage of having narrow pulse width which makes them suitable for remote sensing of vital signals. In this paper a novel approach to estimate periodic motion rates, using ultra wide band (UWB) signals is proposed. The proposed algorithm which is based on wavelet transform is used as a non-contact tool for measurement

Mehran Baboli; Seyed Ali Ghorashi; Namdar Saniei; Alireza Ahmadian

2009-01-01

200

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

201

A remotely UHF powered UWB transmitter for high precision localization of RFID tag  

Microsoft Academic Search

The design of a remotely UHF powered UWB transmitter is presented in 0.13µm CMOS standard process. Power harvesting unit is based on a Dickson voltage multiplier and UWB pulse generator uses filtered combined edge method. Multi-Vt technique and CMOS logic allows pulse generator power consumption between two consecutive pulses to be reduced enough to be remotely powered. It achieves FCC

R. Vauche; E. Bergeret; J. Gaubert; S. Bourdel; O. Fourquin; N. Dehaese

2011-01-01

202

A multiuser detector based on artificial bee colony algorithm for DS-UWB systems.  

PubMed

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. PMID:23983638

Yin, Zhendong; Liu, Xiaohui; Wu, Zhilu

2013-01-01

203

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

204

Symbol Synchronization in Coded UWB Systems using Adaptive Iterative Detection Durai Thirupathi and Keith M. Chugg  

E-print Network

common UWB system found in the literature, the impulse radio, uses very narrow pulses as a way to expand significantly degrading the perfor- mance. I. INTRODUCTION After the discovery of turbo codes [1], iterative

Southern California, University of

205

Harmonic Path (HAPA) Algorithm for Noncontact Vital Signs Monitoring with IRUWB Radar  

E-print Network

is needed not only for patient's comfort but also their safety. Impulse Radio Ultra-Wideband (IR-UWB) radar. INTRODUCTION Vital sign monitoring is fundamental in health care as knowledge of the patient's heart rate (HR consistently and accurately [1]. Currently the most common form of vital sign monitoring in hospitals is pulse

Ingram, Mary Ann

206

Tightly-coupled GPS/UWB Integration  

E-print Network

Tightly-coupled GPS/UWB Integration Glenn MacGougan1 , Kyle O'Keefe1 , and Richard Klukas2 1-phase GPS positioning. A commercially available UWB ranging system is used in a tightly-coupled GPS and UWB with GPS alone. In kinematic testing in a degraded GPS environment, sub-decimetre accuracy was maintained

Calgary, University of

207

Thomas Kaiser Panel Statements UWB Workshop  

E-print Network

DP caused by the antenna pattern TX RX Reflector #12;Slide 8 Thomas Kaiser Panel Statements ­ UWB antennas 1. Direct path arrives first #12;Slide 10 Thomas Kaiser Panel Statements ­ UWB Workshop Santa Thomas Kaiser Panel Statements ­ UWB Workshop Santa Monica, April 11-12, 2006 Bowtie Antenna Simulation

Southern California, University of

208

UWB Radio Workshop 11 April 06  

E-print Network

UWB Radio Workshop 11 April 06 UWB Radio Panel Brian M. Sadler Army Research Laboratory Adelphi, MD Range UWB Communications · Bandwidth stresses antenna, analog front end, ADC ­ especially for low power ·Multi-antenna ­MIMO, diversity, directional ·Time reversal & training ·Radar-like systems ­Low

Southern California, University of

209

UWB: Success in AircraftUWB: Success in Aircraft Shielding MetrologyShielding Metrology  

E-print Network

UWB: Success in AircraftUWB: Success in Aircraft Shielding MetrologyShielding Metrology Dr. Robert in UWB metrology have been existence since 1971--both conducted & radiated · Low-power & low interference processing · NASA: Shuttle safety during night launches · Boeing: protection of flight platforms with high

Southern California, University of

210

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

211

A 0.6-V Low Power UWB CMOS LNA  

Microsoft Academic Search

This paper presents the design of a low-power ultra-wideband low noise amplifier in 0.18-mum CMOS technology. The inductive degeneration is applied to the conventional distributed amplifier design to reduce the broadband noise figure under low power operation condition. A common-source amplifier is cascaded to the distributed amplifier to improve the gain at high frequency and extend the bandwidth. Operated at

Yueh-Hua Yu; Yi-Jan Emery Chen; Deukhyoun Heo

2007-01-01

212

CIRCULAR FRACTAL MONOPOLE ANTENNA FOR LOW VSWR UWB APPLICATIONS  

Microsoft Academic Search

Abstract—A new circular ultra-wideband fractal monopole antenna based on descartes circle theorem (DCT) with elliptical iterations is presented. The proposed fractal design is optimized for return loss below ?15 dB. The basic structure is slightly modified to ensure an overall smooth current distribution limited by the junction point nature of the fractal geometries. The measured return loss of the proposed

Salman Naeem Khan; Jun Hu; Jiang Xiong; Sailing He

2008-01-01

213

Closed-form approximations for link loss in a UWB radio system using small antennas  

Microsoft Academic Search

A critical need in the evaluation of an ultrawideband (UWB) radio system is the calculation of the energy link loss between the source at the transmit antenna and the receiver load. While the rigorous calculation of link loss in a wideband pulsed system requires a full transient electromagnetic solution for the transmit and receive antennas, we show in this paper

David M. Pozar

2003-01-01

214

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

215

UWB Workshop in Santa Monica2006/4/12 Yokogawa Corporation Page1 Japanese Scene & UWB in future  

E-print Network

UWB Workshop in Santa Monica2006/4/12 Yokogawa Corporation Page1 Japanese Scene & UWB in future in Santa MonicaPage2 Japanese scene toward UWB Rule Rule Making efforts since late 2002 Government;2006/4/12 Yokogawa Corporation UWB Workshop in Santa MonicaPage3 FCC mask & ITU interference assessment FCC ITU

Southern California, University of

216

Characteristics of trap-filled gallium arsenide photoconductive switches used in high gain pulsed power applications  

SciTech Connect

The electrical properties of semi-insulating (SI) Gallium Arsenide (GaAs) have been investigated for some time, particularly for its application as a substrate in microelectronics. Of late this material has found a variety of applications other than as an isolation region between devices, or the substrate of an active device. High resistivity SI GaAs is increasingly being used in charged particle detectors and photoconductive semiconductor switches (PCSS). PCSS made from these materials operating in both the linear and non-linear modes have applications such as firing sets, as drivers for lasers, and in high impedance, low current Q-switches or Pockels cells. In the non-linear mode, it has also been used in a system to generate Ultra-Wideband (UWB) High Power Microwaves (HPM). The choice of GaAs over silicon offers the advantage that its material properties allow for fast, repetitive switching action. Furthermore photoconductive switches have advantages over conventional switches such as improved jitter, better impedance matching, compact size, and in some cases, lower laser energy requirement for switching action. The rise time of the PCSS is an important parameter that affects the maximum energy transferred to the load and it depends, in addition to other parameters, on the bias or the average field across the switch. High field operation has been an important goal in PCSS research. Due to surface flashover or premature material breakdown at higher voltages, most PCSS, especially those used in high power operation, need to operate well below the inherent breakdown voltage of the material. The lifetime or the total number of switching operations before breakdown, is another important switch parameter that needs to be considered for operation at high bias conditions. A lifetime of {approximately} 10{sup 4} shots has been reported for PCSS's used in UWB-HPM generation [5], while it has exceeded 10{sup 8} shots for electro-optic drivers. Much effort is currently being channeled in the study related to improvements of these two parameters high bias operation and lifetime improvement for switches used in pulsed power applications. The contact material and profiles are another important area of study. Although these problems are being pursued through the incorporation of different contact materials and introducing doping near contacts, it is important that the switch properties and the conduction mechanism in these switches be well understood such that the basic nature of the problems can be properly addressed. In this paper the authors report on these two basic issues related to the device operation, i.e., mechanisms for increasing the hold-off characteristics through neutron irradiation, and the analysis of transport processes at varying field conditions in trap dominated SI GaAs in order to identify the breakdown mechanism during device operation. It is expected that this study would result in a better understanding of photoconductive switches, specifically those used in high power operation.

ISLAM,N.E.; SCHAMILOGLU,E.; MAR,ALAN; LOUBRIEL,GUILLERMO M.; ZUTAVERN,FRED J.; JOSHI,R.P.

2000-05-30

217

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

218

Design and implementation of a digital impulse generator for a 24GHz UWB radar  

NASA Astrophysics Data System (ADS)

In this paper, we design and implement a digital impulse generator using a DCM block and an OSERDES block for a 24GHz UWB impulse-Doppler radar. The Federal Communications Commission (FCC) has confirmed the spectrum from 22 to 29GHz for UWB radar with a limit power of -41.3dBm/MHz. UWB signal possesses an absolute bandwidth larger than 500MHz or a relative bandwidth up to 20%. The vehicle radar is the key technology with the inherent advantage detected the distance and the velocity regardless of weather. Radar has a role to measure the distance and the velocity of long-distance vehicle. But, the radar with 1m resolution is difficult to satisfy the detection performance in the blind spot zone because the blind spot zone needs high resolution. So, UWB impulse-Doppler radar with 30cm resolution is suitable for the blind spot zone. The designed impulse generator has a 2ns pulse width and 100us PRI. We perform simulations through Xilinx ISE; experiments use a spectrum analyzer and a digital oscilloscope. For UWB radar, we use an AD9779 DAC module with a 1Gsps maximum sampling rate. For equipment, we use a TDS5104B oscilloscope of Tektronix with 3dB bandwidth at 1GHz for the analysis of the time domain and an E4448A spectrum analyzer of Agilent with a 50GHz spectrum for the analysis of the frequency domain. The results of the digital impulse measurement show a 2ns pulse width in the time domain, a 500MHz bandwidth, and a 10KHz spectrum peak in the frequency domain.

Kim, Sang-Dong; Lee, Jong-Hun

2011-06-01

219

NOTE ON ANTENNA DESIGN IN UWB WIRELESS COMMUNICATION SYSTEMS  

E-print Network

-wideband (UWB) radio has a long history from the 1960s, in radar and communication appli- cations [1 antenna shares the same history with UWB radio since it is an indispensable component in UWB systems.Y.W. Chia1 1 Department of Radio Systems, Institute for Infocomm Research 20 Science Park Road, #02

Arslan, Hüseyin

220

Abstract -This paper explores a correlation timing detector for tracking of Ultra-Wide-Band (UWB) monocycle signals. We seek  

E-print Network

obtained in an indoor office environment. The UWB monocycle model, though an idealized representation monocycle tracking include the low duty cycle and the significantly larger bandwidth in the latter. Consequently the effect of pulse shaping by the antenna cannot be ignored, and it is no longer adequate

Southern California, University of

221

ULTRA WIDEBAND FRACTAL MICROSTRIP ANTENNA DESIGN  

Microsoft Academic Search

Abstract—Newfractal geometry for microstrip antennas is presented in this paper. This fractal structure is implemented on hexagonal and,several iteration is applied on initial shape.,This antenna has lowprofile, lightw eight and is easy to be fabricated and has successfully demonstrated multiband and broadband characteristics. The simulated results showthat proposed antenna has very good performance in impedance bandwidth and radiation pattern.

Abolfazl Azari; Javad Rowhani

2008-01-01

222

All-optical UWB generation and modulation using SOA-XPM effect and DWDM-based multi-channel frequency discrimination.  

PubMed

An all-optical UWB pulses generation and modulation scheme using cross phase modulation (XPM) effect of semiconductor optical amplifier (SOA) and DWDM-based multi-channel frequency discrimination is proposed and demonstrated, which has potential application in multiuser UWB-Over-Fiber communication systems. When a Gaussian pulse light and a wavelength-tunable CW probe light are together injected into the SOA, the probe light out from the SOA will have a temporal chirp due to SOA-XPM effect. When the chirped probe light is tuned to the slopes of single DWDM channel transmittance curve, the optical phase modulation to intensity modulation conversion is achieved at DWDM that serves as a multi-channel frequency discriminator, the inverted polarity Gaussian monocycle and doublet pulse is detected by a photodetector, respectively. If the probe lights are simultaneously aimed to different slopes of several DWDM channels, multi-channel or binary-phase-coded UWB signal generation can be acquired. Using proposed scheme, pulse amplitude modulation (PAM), pulse polarity modulation (PPM) and pulse shape modulation (PSM) to UWB pulses also can be conveniently realized. PMID:21164805

Wang, Fei; Dong, Jianji; Xu, Enming; Zhang, Xinliang

2010-11-22

223

UWB Staircase-Profile Printed Monopole Design  

Microsoft Academic Search

In printed monopoles, the current distribution along the lower monopole sheet and upper groundplane edges can be made analogous to a transmission line distribution by an appropriate antenna feed design. Accordingly, the VSWR < 2 impedance bandwidth upper frequency limit can be estimated for staircase-profile printed 2D ultrawideband (UWB) monopoles. Following this guideline, three tailored-bandwidth prototypes are designed, implemented and

Daniel Valderas; Raúl Álvarez; Juan Melendez; Iaki Gurutzeaga; Jon Legarda; Juan I. Sancho

2008-01-01

224

Uniplanar Log-Periodic Slot Antenna Fed by a CPW for UWB Applications  

Microsoft Academic Search

A coplanar waveguide-fed uniplanar log-periodic slot antenna suitable for use in the ultra-wideband radio systems is presented. The in-band impedances and radiation performances are quite stable and satisfactory. A rejected narrow frequency band is further obtained within the wide bandwidth by inserting a pair of metallic stubs into two vertical slots of the proposed antenna. Experimental results reveal that the

Shih-Yuan Chen; Po-Hsiang Wang; Powen Hsu

2006-01-01

225

Multiscale energy products for TOA estimation in IR-UWB systems  

Microsoft Academic Search

In this paper, we consider time of arrival estimation of ultra-wideband signals based on low-rate samples that are obtained after a square-law device. Signal conditioning techniques based on a bank of cascaded multi-scale energy collection filters and wavelets are introduced, where correlations across multiple scales are exploited for edge and peak enhancements towards a more accurate detection. The performances of

I. Guvenc; Z. Sahinoglu

2005-01-01

226

Tremor Acquisition System Based on UWB Wireless Sensor Network  

Microsoft Academic Search

This work suggests to quantify and analyze tremorusing an Ultra Wide-Band (UWB) Wireless Sensor Network(WSN). WSN based on UWB technology provides a new technology for non contact tremor assessment with extremely low radiation and penetration through walls. Tremor is the target symptom in the treatment of many neurological disorders such as Parkinson's disease (PD), midbrain tremor, essential tremor (ET) and

Gaddi Blumrosen; Moshe Uziel; Boris Rubinsky; Dana Porrat

2010-01-01

227

Testing and Research on Interference to GPS from UWB Transmitters  

E-print Network

is similar to the ones that will find application in cell phones and therefore will deliver E-911 location of the tests described in this paper measured UWB impact on the accuracy and loss-of-lock performance of a high-grade GPS aviation receiver. A smaller test set measured UWB impact on the loss-of-lock performance for two

Stanford University

228

UWB radar technique for arc detection in coaxial cables  

NASA Astrophysics Data System (ADS)

UWB signals constituted by a sequence of chips (properly chosen to reduce side lobes and to improve detection accuracy) are transmitted along the transmission lines at a specified Pulse Repetition Frequency (PRF) and their echoes are received by means of directional couplers. The core of the receiver is an ultra high-speed correlator implemented in a Digital Signal Processor (DSP). When a target (arc) is detected, its position and its ``radar cross section'' are calculated to be able to provide the arc position along the transmission line and to be able to classify the type of detected arc. The ``background scattering'' is routinely extracted from the received signal at any pulse. This permits to be resilient to the background structure of transmission lines (bends, junctions, windows, etc.). Thanks to the localization feature, segmentation is also possible for creating sensed and non- sensed zones (for example, to be insensitive to antenna load variations). A complete test bed has been installed using standard coaxial cables (RG58) to demonstrate the system capabilities.

Salvador, Sara; Maggiora, Riccardo

2010-11-01

229

Distributed MAC protocol for networks with multipacket reception capability and spatially distributed nodes  

E-print Network

The physical layer of future wireless networks will be based on novel radio technologies such as Ultra-Wideband (UWB) and Multiple-Input Multiple-Output (MIMO). One of the important capabilities of such technologies is the ...

Celik, Guner Dincer

2007-01-01

230

47 CFR 15.513 - Technical requirements for medical imaging systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Technical requirements for medical imaging systems. 15.513 Section 15.513...Ultra-Wideband Operation § 15.513 Technical requirements for medical imaging systems. (a) The UWB bandwidth of...

2010-10-01

231

47 CFR 15.511 - Technical requirements for surveillance systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Technical requirements for surveillance systems. 15.511 Section 15.511 ...Ultra-Wideband Operation § 15.511 Technical requirements for surveillance systems. (a) The UWB bandwidth of...

2010-10-01

232

Frequency-aware rate adaptation and MAC protocol  

E-print Network

There has been burgeoning interest in wireless technologies that can use wider frequency spectrum. Technology advances, such as 802.11n and ultra-wideband (UWB), are pushing toward wider frequency bands. The analog-to-digital ...

Rahul, Hariharan Shankar

233

Breakdown Behavior of a Wireless Communication Network Under UWB Impact  

NASA Astrophysics Data System (ADS)

Systems with high priority to safety and reliability such as monitoring systems on airports have to work properly. Fast information transmission, continuous access to databases, as well as the management of air traffic are most important for effective and safe operation. Sources of Intentional Electromagnetic Interference can be manufactured relatively easy using commercially available components by civilian persons with relevant expertise and can be used for sabotage or blackmail purposes. For analyzing the weak points of a system existing on airports, it is necessary to reproduce its setup. In this investigation a UHF transmitter of a wireless communication device is developed and its breakdown behavior to unipolar fast rise pulses (UWB) is determined. A breakdown is a non-permanent damage, but includes a type of upset, that requires manual reset or at least stops communications for some period of time. The transmitter consists of three main components connected by data cables: power supply, microcontroller, and loop antenna. The immunity tests are accomplished as a function of the electromagnetic field direction to the device using an open TEM waveguide.

Rohe, M.; Koch, M.

234

MAC Design in Pulse-Based Communication Systems Maria-Gabriella Di Benedetto, Senior Member, IEEE, and Luca De Nardis, Member, IEEE  

E-print Network

ICTON 2007 MAC Design in Pulse-Based Communication Systems Maria-Gabriella Di Benedetto, Senior layers' design. This work addresses Medium Access Control (MAC) issues for IR-UWB communication systems-UWB system are presented, and solutions proposed for such systems at the MAC layer are reviewed

Di Benedetto, Maria-Gabriella

235

Low-power impulse UWB architectures and circuits  

E-print Network

Ultra-wide-band (UWB) communication has a variety of applications ranging from wireless USB to radio frequency (RF) identification tags. For many of these applications, energy is critical due to the fact that the radios ...

Chandrakasan, Anantha P.

236

Time of Arrival Estimation for UWB Localizers in Realistic Environments  

E-print Network

This paper investigates time of arrival (ToA) estimation methods for ultra-wide bandwidth (UWB) propagation signals. Different algorithms are implemented in order to detect the direct path in a dense multipath environment. ...

Falsi, Chiara

237

A new 2-cluster model for indoor UWB channel measurements  

Microsoft Academic Search

The paper describes a new model for the indoor non-line-of-sight (NLOS) UWB channel based on measurements. To date, the Saleh-Valenzuela model (Saleh, A.A. and Valenzuela, R.A., IEEE J. Selected Areas in Commun., vol.SAC-5, no.2, p.128-37, 1987) has been the standard model for indoor NLOS wireless propagation. However, we show that for our set of indoor NLOS UWB channel measurements, better

Swaroop Venkatesh; Jihad Ibrahim; R. Michael Buehrer

2004-01-01

238

Optimisation of low power Radio-over-fibre links for UWB systems  

Microsoft Academic Search

This paper focuses on the design of Radio-over-fibre (ROF) links for ultrawideband (UWB) applications. Due to strict regulations, network architecture and technical feasibility, UWB ROF links must have 0 dB gain, low noise figure and low DC power dissipation. Due to the low power of UWB signals, pre- amplification is possible. Design rules for UWB ROF links with a pre-amplifier

Vit Sipal; David Edwards; Ben Allen

2011-01-01

239

UWB EMI to aircraft radios: field evaluation on operational commercial transport airplanes  

Microsoft Academic Search

Ultrawideband (UWB) transmitters can soon be integrated into a wide variety of portable electronic devices (PED) that passengers routinely carry on board commercial airplanes. 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. The approach of this study was

Jay J. Ely; Warren L. Martin; Gerald L. Fuller; Timothy W. Shaver; J. Zimmerman; W. E. Larsen

2004-01-01

240

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 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...

2012-10-01

241

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

242

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

Code of Federal Regulations, 2011 CFR

...2011-10-01 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 relatively...

2011-10-01

243

Distribution of Double-Sideband OFDM-UWB Radio Signals in Dispersion Compensated Long-Reach PONs  

Microsoft Academic Search

The performance of orthogonal frequency division multiplexing ultra wideband radio signals distribution in dis- persion compensated (DC) long-reach passive optical networks (LR-PONs) is assessed numerically for conventional chirpless Mach-Zehnder (MZ) and chirped linearized (L) electro-optic modulators (EOMs). The optimum modulation index and the minimum required optical signal-to-noise ratio are evaluated for optical network units (ONUs) at different distances from the

Tiago Alves; Adolfo Cartaxo

2011-01-01

244

UWB and 60-GHz RF generation and transmission over WDM-PON based on bidirectional asymmetric polarization modulation and frequency multiplication  

NASA Astrophysics Data System (ADS)

A novel scheme to simultaneously provide UWB, 60-GHz millimeter-wave (mmW), and baseband services over a wavelength division multiplexing (WDM) passive optical network (PON) is proposed and demonstrated. In the proposed system, an OOK Gaussian pulse signal is modulated on the optical carrier and then converted to an OOK UWB impulse signal at an edge filter, a baseband signal and a 30-GHz signal are then modulated on the same optical carrier. By employing polarization multiplex technique, the UWB and baseband signal will have orthogonal polarization directions and the spectrum interference between the two signals is avoided. By suppressing the optical carrier, a frequencydoubled mmW signal at 60 GHz is generated by beating the two 1st order sidebands at a photodetector (PD). Error-free transmission of a UWB signal at 2.5 Gbps and a wired baseband signal at 2.5 and 5 Gbps over a 25-km single-mode fiber (SMF) is achieved. A frequency-doubled mmW signal at 60 GHz is also obtained.

Liu, Weilin; Yao, Jianping

2013-10-01

245

Optimised implementation of a matched filter bank for ultrawideband radios  

NASA Astrophysics Data System (ADS)

Ultra-wideband (UWB) technology dates back to early 1980s and was originally employed in radar applications. Unlike any narrowband or broadband communication systems, an UWB system does not employ any radio frequency (RF) carrier for data transmission. Instead it uses very short period electrical pulses in the order of hundreds of pico-seconds to few nano-seconds, which justifies the availability of an ultra-high bandwidth. From a hardware implementation viewpoint, UWB system design presents many challenges such as synchronisation, power limitation and receiver design. However, the design of an UWB transceiver is less complex given the fact that the RF carrier is eliminated. In an UWB transceiver, most of the processing is performed in the digital baseband while the analog front end is responsible for amplification, filtering and quantisation. A bank of matched filters constitutes the major portion of digital baseband section in an UWB transceiver. This paper presents the design, optimisation and field programmable gate array (FPGA) implementation of the matched filter bank as an attempt to minimise the overall circuit complexity, achieve higher data rates and low power consumption in UWB radios.

Muthuswamy, Sivanandan; Veljanovski, Ronny; Singh, Jugdutt

2005-02-01

246

Three-Dimensional FDTD Simulation of Biomaterial Exposure to Electromagnetic Nanopulses  

E-print Network

Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, have been recently approved by the Federal Communications Commission for a number of various applications. They are also being explored for applications in biotechnology and medicine. The simulation of the propagation of a nanopulse through biological matter, previously performed using a two-dimensional finite difference-time domain method (FDTD), has been extended here into a full three-dimensional computation. To account for the UWB frequency range, a geometrical resolution of the exposed sample was $0.25 mm$, and the dielectric properties of biological matter were accurately described in terms of the Debye model. The results obtained from three-dimensional computation support the previously obtained results: the electromagnetic field inside a biological tissue depends on the incident pulse rise time and width, with increased importance of the rise time as the conductivity increases; no thermal effects are possible for the lo...

Simicevic, N

2005-01-01

247

Modeling MIMO-UWB OFDM systems with Computational Electromagnetics  

Microsoft Academic Search

This paper simulates a typical indoor MIMO-UWB OFDM system using computational electromagnetics. The goal is to create a simulation using a real world environment and taking into account realistic antenna effects. The effects of the wireless channel are examined on a per subcarrier basis. Analysis of the simulation results shows that the channel response and subsequently, mutual information is highly

Rocco Dragone; John Kountouriotis; Prathaban Mookiah; Kapil R. Dandekar

2007-01-01

248

UWB: Fostering Innovation Through a Balanced Regulatory Framework  

E-print Network

) ­ U.S. Radar (ground penetrating radar) · May 2000 ­ Notice of Proposed Rule Making (NPRM) ­ UWB, and authorized three classes of systems: · Imaging systems (ground penetrating radar, wall and through SUMMARY TABLE GROUND PENETRATING RADARS (GPR) AND WALL IMAGING SYSTEMS THROUGH-WALL IMAGING SYSTEMS (1

Southern California, University of

249

Generation of ultrawideband pulses using a distributed fiber-link system  

NASA Astrophysics Data System (ADS)

This work develops a simple distributed fiber-link system with a newly designed antenna to generate ultrawideband (UWB) pulses for indoor wireless communications. The proposed system comprises a gain-switched distributed feedback laser diode (DFB-LD), electro-absorption modulator (EAM), a photodetector and a pair of coplanar waveguide (CPW) antennas. This optical approach can tolerate pulse dispersion and prevent the generation of intersymbol interference (ISI), since the optical pulse width is easily adjustable, providing better radio communication, as determined by the generation of UWB signal. Furthermore, the simulated and experimental results demonstrate that the proposed system can generate high-quality UWB pulse signals for application to future indoor high-bit-rate wireless communications.

Lin, Wen-Piao; Li, Ruei Chi

2008-07-01

250

Ultra-wideband WDM transmission using cascaded chirped fiber gratings  

Microsoft Academic Search

We demonstrate 32 channel WDM transmission at a per-channel rate of 10 Gb\\/s over 375 km (five amplified fiber spans) of conventional fiber. Chirped-fiber-grating modules provide dispersion compensation over an 18-nm bandwidth, and a swept-frequency measurement confirms continuous good performance across the entire band

L. D. Garrett; A. H. Gnauck; R. W. Tkach; B. Agogliati; L. Arcangeli; D. Scarano; V. Gusmeroli; C. Tosetti; G. Di Maio; F. Forghieri

1999-01-01

251

Ultra wideband antenna array processing under spatial aliasing  

E-print Network

in Vm;l, which is centered at ! = ?2!l. Hence, Um;l(!), the spectrum of the flltered signal vm;l(t), would be: Um;l(!) = Hm;l(! +!l)Sl(!)e?j(!+!l)?m +Emf(! +!l) ; (2.12) in which Emf(!+!l) is the noise component after passing through the demodulator.... Under a quite general scenario, (to be discussed in the sequel), we can approximate (2.12) by the following equation: Um;l(!) ? Hm(!l)Sl(!)e?j!l?m +Emf(! +!l) ; (2.13) which assumes the time domain equivalent expression: um(t) = H(!l)sl(t)e?j!l?m +emf...

Shapoury, Alireza

2009-05-15

252

Signal Generation for FMCW Ultra-Wideband Radar  

E-print Network

One of the greatest concerns facing the planet earth today is global warming. Globally the temperatures have risen and this has caused rise in sea level. Since a large percentage of the population lives near the coast sea ...

Patel, Aqsa Ejaz

2009-01-01

253

Ultra wideband technology for aircraft wireless intercommunications systems (AWICS) design  

Microsoft Academic Search

Current intercommunications system (ICS) designs for military, multicrew aircraft utilize lengthy, encumbering cords to physically attach the crewmember's helmet or headset to a distributed audio intercom system. Typical ICS long-cords are approximately 100 feet in length and allow crewmembers to maintain communications as they move about the aircraft while performing their mission duties. These cords also allow crewmembers to maintain

Aitan Ameti; Robert J. Fontana; E. J. Knight; Edward Richley

2004-01-01

254

75 FR 62476 - Ultra-Wideband Transmission Systems  

Federal Register 2010, 2011, 2012, 2013

...potential for interference to C-band fixed satellite and cellular operations. Background 2. On February 14, 2002, the Commission...Commission stated that these results are consistent with the theory, as expressed by NTIA, that RMS measured emission...

2010-10-12

255

Reconnaissance with ultra wideband UHF synthetic aperture radar  

Microsoft Academic Search

The author addresses the problem of detecting and identifying stationary and moving targets with foliage penetrating UHF synthetic aperture radar (SAR). The role of a target's coherent SAR signature, which varies with the radar's frequency and aspect angle, in forming the Fourier space of the SAR signal is analyzed. The resultant relationship is the basis of an algorithm which, after

MEHRDAD SOUMEKH

1995-01-01

256

UNIVERSIDAD AUTONOMA DE MADRID ESCUELA POLITECNICA SUPERIOR  

E-print Network

NUEVAS ESTRUCTURAS DE ANTENAS ULTRA WIDEBAND Jorge Cámara Fernández Marzo 2011 #12;I #12;II DISE�O DE NUEVAS ESTRUCTURAS DE ANTENAS ULTRA WIDEBAND AUTOR: Jorge Cámara Fernández TUTOR: José Luis Masa Campos;Diseño de nuevas estructuras de antenas de UWB Jorge Cámara Fernández IV Resumen En este proyecto se

Autonoma de Madrid, Universidad

257

Improved GPR data preprocessing for detection of various land mines  

Microsoft Academic Search

In this paper, we present a comprehensive two-dimensional technique for preprocessing the data acquired by a continuously moving ultra wideband impulse ground penetrating radar (CM UWB IGPR). The UWB IGPR was developed by the International Research Centre for Telecommunications- transmission and Radar especially for humanitarian land mine detection. The radar was used to collect data in the measurement campaigns which

B. Sai; Leo P. Ligthart

2000-01-01

258

An ML Timing Estimator in UWB Communication Systems  

NASA Astrophysics Data System (ADS)

The problem of estimating the timing of ultra-wide band signal is considered in the letter. We develop a maximum likelihood timing estimation algorithm for binary PAM DS-UWB systems. The derivation of the proposed algorithm is based on the known training sequence and AWGN channel. The Cramér-Rao Bound (CRB) for the ML timing estimator is presented as a performance benchmark. It is found via numerical results that the ML timing estimator on AWGN channels achieves the CRB when the values of Eb/N0 for the observation bits Nb=50 are sufficiently high. Finally, the performance of the proposed ML estimator is evaluated on actual channels with intersymbol interference such as an IEEE UWB indoor multipath channel model.

Kim, Sangchoon; Son, Kyoungsoo; Kang, Bongsoon

259

Empirical UWB path loss models for typical office environments  

Microsoft Academic Search

This paper investigates the path loss characteristics of an UWB signal (0.1-2 GHz) in a typical office building. Three statistical path loss models are presented, i.e. the nth power model and two attenuation factor dependent models. Attenuation factor for brick and gypsum wall, the two main obstructive walls in this experiment were investigated assuming free space path loss. Attenuation factor

Sharlene Thiagarajah; B. M. Ali; M. Ismail

2005-01-01

260

Design of a CPW-feed circularly polarized slot antenna with triangle embedded in half circular disc for UWB applications  

NASA Astrophysics Data System (ADS)

A compact (40 mm x 35 mm) coplanar waveguide (CPW) fed slot antenna for circular polarization is presented in this paper. The antenna is designed and fabricated for applications in the ultra-wideband domain of wireless communications where circular polarization is also required. The axial ratio (AR) bandwidth of the proposed antenna is 35.46% (5.8 GHz- 8.3 GHz), while the experimental impedance bandwidth is from 2.8 GHz - 8.6 GHz. The experimental results are very close to the simulated results. The antenna displays a stable radiation pattern and a moderately high gain of around 5 - 6 dB in the useful band.

Krishna, Ram; Kumar, Raj

2013-01-01

261

47 CFR 15.521 - Technical requirements applicable to all UWB devices.  

Code of Federal Regulations, 2010 CFR

...15.521 Technical requirements applicable to all UWB devices. (a) UWB devices may not be employed for the operation of toys. Operation onboard an aircraft, a ship or a satellite is prohibited. (b) Manufacturers and users are reminded of the...

2010-10-01

262

Wireless field bus communication with software defined IR-UWB in a manufacturing environment  

Microsoft Academic Search

This paper elaborates a concept for a wireless field bus communication with software defined ultra wide band with impulse radio modulation (IR-UWB) in manufacturing environments. A wireless field bus offers an important improvement to the smart factory due to increasing requirements for connectivity, adaptability and flexibility. Former analysis showed the benefit of using UWB technology for the wireless field bus

T. Alpert; F. Lang; M. Gro?zing; M. Berroth

2010-01-01

263

On the MAC Layer Performance of Time-Hopped UWB Ad Hoc Networks  

E-print Network

the impact of the multipath delay spread on the MAC layer performance of time-hopped impulse-based UWB ad hoc on investigating the effects of the multipath delay spread on the performance at the MAC layer in impulse- based UWB ad hoc networks. Our motivation stems from the fact due to delay spread, multiple time

Krishnamurthy, Srikanth

264

FDTD simulation of exposure of biological material to electromagnetic nanopulses  

NASA Astrophysics Data System (ADS)

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 biological matter in terms of the Debye model without loss of accuracy. Several tissue types have been considered. Results show that the electromagnetic field inside biological tissue depends on incident pulse rise time and width. Rise time dominates pulse behaviour inside tissue as conductivity increases. It has also been found that the amount of energy deposited by 20 kV m-1 nanopulses is insufficient to change the temperature of the exposed material for pulse repetition rates of 1 MHz or less, consistent with recent experimental results.

Simicevic, Neven; Haynie, Donald T.

2005-01-01

265

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

266

Distortion effects in a switch array UWB radar for time-lapse imaging of human heartbeats  

NASA Astrophysics Data System (ADS)

Cardiovascular diseases (CVD) are a major cause of deaths all over the world. Microwave radar can be an alternative sensor for heart diagnostics and monitoring in modern healthcare that aids early detection of CVD symptoms. In this paper measurements from a switch array radar system are presented. This UWB system operates below 3 GHz and does time-lapse imaging of the beating heart inside the human body. The array consists of eight fat dipole elements. With a switch system, every possible sequence of transmit/receive element pairs can be selected to build a radar image from the recordings. To make the radar waves penetrate the human tissue, the antenna array is placed in contact with the body. Removal of the direct signal leakage through the antennas and body surface are done by high-pass (HP) filtering of the data prior to image processing. To analyze the results, measurements of moving spheres in air and simulations are carried out. We see that removal of the direct signal introduces amplitude distortion in the images. In addition, the effect of small target motion between the collection times of data from the individual elements is analyzed. With low pulse repetition frequency (PRF) this motion will distort the image. By using data from real measurements of heart motion in simulations, we analyze how the PRF and the antenna geometry influence this distortions.

Brovoll, Sverre; Berger, Tor; Aardal, Åyvind; Lande, Tor S.; Hamran, Svein-Erik

2014-05-01

267

Performance of Coherent Receivers for PCTH-Based UWB System with Diversiform Modulation Schemes  

NASA Astrophysics Data System (ADS)

The performances of a PCTH-based communication UWB system with diversiform modulation schemes are compared on the classic AWGN channel propagation and the realistic IEEE-UWB channel model. By employing different versions of modulation at the transmitters, the performances of an optimal receiver and a Rake receiver with various combining schemes are studied in this paper. The numerical results for several compared cases illustrate the tradeoff between transmitter diversity and receiver complexity. It is shown that the actual performance of the PAM-PCTH scheme can be better in both kinds of channel propagation. We also find that the PCTH-based UWB system with the Rake receiver has better performance than the conventional proposal for overcoming the multipath propagation effects in the UWB indoor environment.

Gong, Yun-Rui; He, Di; He, Chen; Jiang, Ling-Ge

268

UWB-IR Interference Mitigation Using Multi-Carrier Templates in Frequency Dependent Path Loss Environment  

Microsoft Academic Search

Performance degradation of UWB-IR wireless systems due to interference from co-existing services is an important issue. To reduce the effect of interference from coexisting sources such as the WLAN standard IEEE 802.11a on UWB Communication, the construction of a modified template waveform using multi-carrier sinusoids was proposed previously. However, that work considered a free space propagation channel model with no

M. K. Lakshmanan; H. Nikookar

2007-01-01

269

Performance of Slotted-Aloha over TH-UWB Hwee-Xian Tan, Ranjeet K. Patro, Mun-Choon Chan, Peng-Yong Kong, Chen-Khong Tham  

E-print Network

-Aloha, an enhanced version of the Aloha MAC protocol, over the TH-UWB physical layer, using both theoretical analysisPerformance of Slotted-Aloha over TH-UWB Hwee-Xian Tan, Ranjeet K. Patro, Mun-Choon Chan, Peng sensing unsuitable for use in UWB systems. In this paper, we study the throughput performance of slotted

Chan, Mun Choon

270

Enabling Next Generation Mobile Wireless DevicesEnabling Next Generation Mobile Wireless Devices Chief Scientist, UWB Wireless Corp.  

E-print Network

2000 1X Ad Hoc Networks GPRS PDC Bluetooth,UWB Research Beyond 3G #12;3G & UWB Wireless Corp. 7 WCDMA Wireless Corp. 8 POTS CATV M M DS Satellite Optical DSL Cable Modem FTTH Broadband (>200Mbps) To The Home

Qiu, Robert Caiming

271

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 -10 dB 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; Redouté, Jean-Michel; Yuce, Mehmet R

2013-01-01

272

Antennas for the detection of radio emission pulses from cosmic-ray induced air showers at the Pierre Auger Observatory  

NASA Astrophysics Data System (ADS)

The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal.

Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Anti?i?, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Bohá?ová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Buroker, L.; Burton, R. E.; Caballero-Mora, K. S.; Caccianiga, B.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; del Río, M.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filip?i?, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gouffon, P.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jansen, S.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; LaHurd, D.; Latronico, L.; Lauer, R.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Meyhandan, R.; Mi?anovi?, S.; Micheletti, M. I.; Minaya, I. A.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Oehlschläger, J.; Olinto, A.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.

2012-10-01

273

Modeling, Real-Time Estimation, and Identification of UWB Indoor Wireless Channels  

SciTech Connect

In this paper, stochastic differential equations (SDEs) are used to model ultrawideband (UWB) indoor wireless channels. We show that the impulse responses for time-varying indoor wireless channels can be approximated in a mean square sense as close as desired by impulse responses that can be realized by SDEs. The state variables represent the inphase and quadrature components of the UWB channel. The expected maximization and extended Kalman filter are employed to recursively identify and estimate the channel parameters and states, respectively, from online received signal strength measured data. Both resolvable and non-resolvable multipath received signals are considered and represented as small-scaled Nakagami fading. The proposed models together with the estimation algorithm are tested using UWB indoor measurement data demonstrating the method s viability and the results are presented.

Olama, Mohammed M [ORNL] [ORNL; Djouadi, Seddik M [ORNL] [ORNL; Li, Yanyan [ORNL] [ORNL; Fathy, Aly [University of Tennessee (UT)] [University of Tennessee (UT)

2013-01-01

274

Design of high speed low voltage data converters for UWB communication systems  

E-print Network

and Doubled Encoder Output by the 2nd Latch Block.....51 Figure 3-21. Encoder and the Proposed 2nd Latch Output at the DSP Sampling Points.52 Figure 3-22. Block Diagram of the 2nd Latch Block.......................................................53 Figure 3... the conceptual UWB communication system [1]. LNA LPF VGA ADC DSP LO UW B receiver LPF LO UW B transm itter Figure 1-1. Transmitter and Receiver for a UWB Communication System This thesis follows the style and format of IEEE Journal of Solid-State Circuits...

Lee, Choong Hoon

2006-08-16

275

Comparison between UWB and CW radar sensors for breath activity monitoring  

NASA Astrophysics Data System (ADS)

In this paper the ability of four radar sensors in detecting breath activity has been tested. In particular, range gating UWB, CMOS UWB, CW phase detecting, and FMCW radars have taken into account. Considering a realistic scenario, the radar antenna has been pointed towards the thorax of a breathing subject and the recorded signals have been compared with those of a piezoelectric belt placed around the thorax. Then the ability of the radars in detecting small movements has been tested by means of an oscillating copper plate placed at various distances from the radar antenna. All the considered radars were able to detect the plate movements with a distance-dependent resolution.

Pisa, Stefano; Bernardi, Paolo; Cicchetti, Renato; Giusto, Roberto; Pittella, Erika; Piuzzi, Emanuele; Testa, Orlandino

2014-05-01

276

47 CFR 15.510 - Technical requirements for through D-wall imaging systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Technical requirements for through D-wall imaging systems. 15.510 Section 15...Ultra-Wideband Operation § 15.510 Technical requirements for through D-wall imaging systems. (a) The UWB...

2010-10-01

277

WiMedia Ultra-Wide Band Transmission in Radio over Fiber using Multimode Fiber  

Microsoft Academic Search

WiMedia compliant Ultra-Wideband signals are transmitted in a low cost Radio over Fiber system over extended distances to 900 m. Measured packet error rate shows the merit of UWB transmission and extension in the ROF medium. Significant range extension has been demonstrated using ROF.

Ming-Li Yee; Yong-Xin Guo; Viet Hung Pham; Ling Chuen Ong

2007-01-01

278

A novel impulse radio network for tactical military wireless communications  

Microsoft Academic Search

Two of the major concerns in tactical military wireless communication networks are covertness and throughput. Impulse radio is an ultra-wideband code division multiple access (UWB-CDMA) technique being considered as the physical layer for future networks. Impulse radio exhibits low power spectral density and relatively high immunity to fading but suffers from relatively long acquisition times. In traditional packet radio networks

Santosh S. Kolenchery; J. K. Townsend; J. A. Freebersyser

1998-01-01

279

A Cold Startup Strategy for Blind Adaptive M-PPM Equalization  

E-print Network

. We explore the behavior of the blind adaptive algorithm when one of the key assumptions necessary or no intersymbol interference (ISI), and thus until recently there had been little motivation to explore by the ultra-wideband (UWB) community for so-called impulse radios [4]. While several studies of ISI

Klein, Andrew G.

280

UWB wireless interconnect scheme for communicating devices within small conducting enclosure  

Microsoft Academic Search

This paper presents a novel concept which proposes the use of an ultra-wide bandwidth (UWB) ultra small scale wireless interconnect scheme for use within a electrically small enclosure. Such ultra small environments (size ? 10 wavelengths) are topologically much more complex, being more cluttered, than typical indoor environments (size ? 10 wavelengths). The concept is presented using an aluminium tower

Javier Gelabert; David Edwards; Christopher J. Stevens

2011-01-01

281

GPS and UWB for indoor navigation Guttorm Ringstad Opshaug and Per Enge  

E-print Network

to multipath that is less than one chip width away from a direct path ray. In the case of GPS CGPS and UWB for indoor navigation Guttorm Ringstad Opshaug and Per Enge Department of Aeronautics would make such an endeavor worthwhile. Some server-based GPS systems, like SnapTrack, already claim

Stanford University

282

Chi-squared distribution approximation for probabilistic energy equalizer implementation in impulse-radio UWB receiver  

Microsoft Academic Search

This paper addresses the hardware implementation feasibility assessment of a probabilistic energy equalizer for UWB impulse radio (IR) transmission. The receiver is based on energy detection and targets data rates greater than 100 Mbps. The aim of this study is to bypass certain complex mathematical functions like the chi-squared (¿2) distribution and approximate it by functions easier to implement. Fixed

Sami Mekki; Jean-Luc Danger; Benoit Miscopein; Joseph J. Boutros

2008-01-01

283

Frequency and MIMO impact on ray tracing based UWB channel modelling  

Microsoft Academic Search

It is a challenging task to handle dense multipath environment in a wireless communication channel. Various techniques were suggested to handle this issue such as power control, antenna, time and frequency diversity etc. However, antenna diversity is considered to be the most practical way to handle multipath fading. In this paper, a deterministic UWB channel model was developed based on

Hafiz M. Asif; Sam Chadwick; Yujie Zeng; Bahram Honary; Hasan Ahmed

2010-01-01

284

An improved classification method of concealed obstacles using UWB radar and stereo cameras  

Microsoft Academic Search

In this paper, an improved method for classifying the concealed obstacles through foliage is newly proposed. For this purpose, forward imaging UWB radar is applied to get the intensity information of obstacles, and CCD cameras is also utilized to get the height information as well. Based on these sensors, a classification method of concealed obstacles is newly derived using the

Dong Won Yang; Seok Jae Lee; Tae Ha Kang; Joo Hong Yoon; Jung Ho Ko

2011-01-01

285

Development of a UWB GPR System for Detecting Small Objects Buried under Ground  

E-print Network

. Shinnae Techno-Town 801, Sangbong, Seoul, 131-220, Korea Abstract A ground penetrating radar (GPR) using ground penetrating radar (GPR) systems have been intensively investigated for mine detection [5]. This paper reports a new application of UWB radar for the detection of gas pipelines buried in the ground

Ha, Dong S.

286

UWB Characteristics of RF Propagation for Body Mounted and Implanted Sensors Submitted to the Faculty  

E-print Network

the human body to another sensor on the body surface or external. From the image data provided1 UWB Characteristics of RF Propagation for Body Mounted and Implanted Sensors by Jin Chen A Thesis of Department #12;2 Abstract Body Area Network (BAN) technology is related to many applications inside

Pahlavan, Kaveh

287

Analysis of Distributed Reservation Protocol for UWB-based WPANs with ECMA-368 MAC  

E-print Network

Analysis of Distributed Reservation Protocol for UWB-based WPANs with ECMA-368 MAC Nasim Arianpoo for the performance analysis of the medium access control (MAC) protocol standardized in ECMA-368. The MAC protocol (MAP) and phase type distribution (PH), we model this MAC layer as a MAP/PH/1 queueing system

Wong, Vincent

288

UWB MISO Time Reversal With Energy Detector Receiver Over ISI Channels  

E-print Network

for the purpose of low complexity at the receiver. This research is motivated by the need for high, these suboptimal schemes' equivalent discrete channels exhibit nonlinear behavior [10][15], which implies that when. The UWB channel impulse response (CIR) contains a large number of resolvable components coming through

Qiu, Robert Caiming

289

Low cost and precise localization in a remote-powered wireless sensor and identification system  

Microsoft Academic Search

A low cost and precise localization system based on a remote-powered UWB-RFID tag is presented for wireless identification, sensing, positioning and tracking. Our contribution is to utilize the Impulse Radio Ultra wideband (IR-UWB) communication in a RFID system. Such as conventional RFIDs, a tag captures energy from the received RF signal transmitted by a reader which also carries data and

Majid Baghaei-Nejad; Li-Rong Zheng

2011-01-01

290

A Compact Cross-Shaped Slot Antenna with a Coplanar Waveguide Fed Rotated Patch for UWB Applications  

NASA Astrophysics Data System (ADS)

In this letter, a compact cross-shaped slot antenna with a coplanar waveguide fed rotated patch is presented and experimentally studied. By properly designing the dimensions of cross-shaped slot and rotated patch, good UWB property can be obtained. In comparison with the previous slot antennas, the proposed antenna has a smaller size as high as 35 mm×33.8 mm. The measured impedance bandwidths, for reflection coefficients less than -10 dB, range from 2.55 to 12.01 GHz, which can cover UWB frequency ranges (3.1-10.6 GHz). Moreover, the novel antenna has nearly omni-directional radiation patterns, steady radiation efficiency and good gains in the UWB ranges. These results prove that the antenna exhibits good characteristics and is suitable for portable mobile ultrawideband (UWB) applications.

Wang, Ping; Wen, Guang-Jun; Jin, Hai-Yan

2012-06-01

291

Preliminary experimental results on the spectrum sensing performances for UWB-Cognitive Radios for detecting IEEE 802.11n systems  

Microsoft Academic Search

In this paper we present the spectrum sensing performance for detecting the IEEE 802.11n Wi-Fi terminals for ultrawideband (UWB) based cognitive radio (CR) systems. The 802.11 n WiFi system lies in the 5 GHz un-licensed frequency band and is subjected to interferences from the UWB transmissions. The UWB based CR terminals perform secondary communications by opportunistically utilizing the available spectrum

Sithamparanathan Kandeepan; Gianmarco Baldini; Radoslaw Piesiewicz

2009-01-01

292

Three-dimensional FDTD simulation of biomaterial exposure to electromagnetic nanopulses  

NASA Astrophysics Data System (ADS)

Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, have recently been approved by the Federal Communications Commission for a number of different applications. They are also being explored for applications in biotechnology and medicine. The simulation of the propagation of a nanopulse through biological matter, previously performed using a two-dimensional finite-difference time-domain (FDTD) method, has been extended here into a full three-dimensional computation. To account for the UWB frequency range, the geometrical resolution of the exposed sample was 0.25 mm and the dielectric properties of biological matter were accurately described in terms of the Debye model. The results obtained from the three-dimensional computation support the previously obtained results: the electromagnetic field inside a biological tissue depends on the incident pulse rise time and width, with increased importance of the rise time as the conductivity increases; no thermal effects are possible for the low pulse repetition rates, supported by recent experiments. New results show that the dielectric sample exposed to nanopulses behaves as a dielectric resonator. For a sample in a cuvette, we obtained the dominant resonant frequency and the Q-factor of the resonator.

Simicevic, Neven

2005-11-01

293

Fabrication of CPW-Fed Fractal Antenna for UWB Applications with Omni-Directional Patterns  

PubMed Central

Novel and compact CPW-fed antennas are proposed comprised of a fractal patch and modified ground-plane. The ground-plane is truncated at the center and includes dielectric notches at its side to enhance the antenna's impedance bandwidth. The dimensions of the notches effectively control the upper and lower band edges of the antenna. The optimized antenna operates across 2.95–12.81?GHz for S11 ? ?10?dB. Omnidirectional radiation pattern is achieved over the full UWB frequency range. The miniaturized antenna has a total size of 14 × 18 × 1?mm3. The characteristics of the proposed antenna are suitable for UWB wireless communication requiring low profile antennas. PMID:24672314

Sedghi, Tohid; Jalali, Mahdi; Aribi, Tohid

2014-01-01

294

Fabrication of CPW-fed fractal antenna for UWB applications with Omni-directional patterns.  

PubMed

Novel and compact CPW-fed antennas are proposed comprised of a fractal patch and modified ground-plane. The ground-plane is truncated at the center and includes dielectric notches at its side to enhance the antenna's impedance bandwidth. The dimensions of the notches effectively control the upper and lower band edges of the antenna. The optimized antenna operates across 2.95-12.81 GHz for S11 ? -10 dB. Omnidirectional radiation pattern is achieved over the full UWB frequency range. The miniaturized antenna has a total size of 14 × 18 × 1 mm(3). The characteristics of the proposed antenna are suitable for UWB wireless communication requiring low profile antennas. PMID:24672314

Sedghi, Tohid; Jalali, Mahdi; Aribi, Tohid

2014-01-01

295

Design and implementation of frequency synthesizers for 3-10 ghz mulitband ofdm uwb communication  

E-print Network

DESIGN AND IMPLEMENTATION OF FREQUENCY SYNTHESIZERS FOR 3-10 GHZ MULTIBAND OFDM UWB COMMUNICATION A Dissertation by CHINMAYA MISHRA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... MISHRA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Edgar S?nchez-Sinencio Committee Members, Jose...

Mishra, Chinmaya

2009-05-15

296

Toward 3D UWB tomographie imaging system for breast tumor detection  

Microsoft Academic Search

A novel 3D tomographic algorithm for short range cylindrical geometries using UWB frequency range is presented. The algorithm has been applied to breast tumor detection, nevertheless, its non application-specific character permits the use in other applications. The detection capability of the tomographic algorithm is proved through numerical simulations and experimental measurements of canonical and more realistic body-attached breast phantoms. For

M. Guardiola; L. Jofre; S. Capdevila; S. Blanch; J. Romeu

2010-01-01

297

Planar-Monopole-Fed, Surface-Mounted Quasi-TEM Horn Antenna for UWB Systems  

Microsoft Academic Search

A compact, quasi-TEM horn antenna is presented. This planar-monopole-fed, surface-mounted, UWB antenna has nearly constant gain of 4.8 ± 0.65 dBi from 2.75-12 GHz. It is ?\\/4 (45 mm) long at the lowest operating frequency. It also has nearly linear phase response in this ultrawideband. The radiation pattern in the azimuth plane is broad and the pattern in the elevation

Y. Ranga; A. K. Verma; Karu P. Esselle

2010-01-01

298

Analysis of the QAC IR-UWB Receiver for Low Energy, Low Data-Rate Communication  

Microsoft Academic Search

The interest in low energy, low data-rate communication is growing steadily, e.g., for use in sensor networks, body area networks, localization. The high energy efficiency required for these applications can only be reached by carefully balancing transceiver complexity, power consumption and performance. The quadrature analog correlation (QAC) receiver is an impulse radio ultra-wide-band (IR-UWB) receiver that pursues this optimal tradeoff.

Marian Verhelst; Wim Dehaene

2008-01-01

299

Application of UWB and GPS technologies for vehicle localization in combined indoor-outdoor environments  

Microsoft Academic Search

Ultra-wide band (UWB) sensors are innovative devices constructed for efficient wireless communications that have recently being used for vehicle localization in indoor environments. In contrast, GPS sensors are well-known satellite-based positioning devices widely extended for outdoor applications. We evaluate in this paper the combination of both technologies for efficient positioning of vehicles in a mixed scenario (both indoor and outdoor

J. A. Fernandez-Madrigal; E. Cruz-Martin; J. Gonzalez; C. Galindo; J. L. Blanco

2007-01-01

300

A Generic Statistical-Based UWB Channel Model for High-Rise Apartments  

Microsoft Academic Search

A generic statistical-based ultrawide-band (UWB) indoor channel model which incorporates the clustering of multipath components (MPCs) is proposed. The model is derived using measurement data collected in the frequency band of 3–10 GHz in various types of high-rise apartment under different propagation scenarios. The measurement procedure allows the characterization of both the large-scale and the small-scale statistics of the channel.

Chia-Chin Chong; Su Khiong Yong

2005-01-01

301

54 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 7, NO. 1, JANUARY 2008 Timing with Dirty Templates for Low-Resolution Digital UWB Receivers  

E-print Network

operational even when the ADC resolution is very low. Index Terms-- Analog-digital conversion, multipath]. In this paper, we investigate TDT algorithms for digital UWB receivers with low-resolution analog-to-digital converters (ADC). Different from the original TDT in [7] for analog UWB receivers, our digital TDT

Yang, Liuqing

302

344 JOURNAL OF COMMUNICATIONS AND NETWORKS, VOL. 5, NO. 4, DECEMBER 2003 Designing Optimal Pulse-Shapers  

E-print Network

) technology is gaining increas- ing interest for its potential application to short-range indoor wire- less- evitably have to overlay existing narrow-band RF services, such as the global positioning system (GPS. The material in this paper was presented in part at the IEEE Conf. on Ultra-Wideband Systems and Technologies

303

EVALUATION OF UWB COMNUNICATION FOR IFE SYSTEM IN THE AIRCRAFT CABINE Roxana Albu, Aubin Lecointre, Daniela Dragomirescu,  

E-print Network

into two separated boxes: one specialized for power and one dedicated to data. · Smart Video Display Unit Unit: this unit is composed of a remote control to interact with the system and an audio jack halEVALUATION OF UWB COMNUNICATION FOR IFE SYSTEM IN THE AIRCRAFT CABINE Roxana Albu, Aubin Lecointre

Paris-Sud XI, Université de

304

A Novel Class of Algorithms for Timing Acquisition of Differential Transmitted Reference UWB Receivers: Architecture, Performance Analysis and System Design  

Microsoft Academic Search

This paper deals with the analysis of the timing acquisition (synchronization) process in Impulse Radio (IR-) Ultra Wide Band (UWB) systems based on Differential Transmitted Reference (DTR) receiver architectures. The fundamental contribution includes a theoretical framework for timing acquisition analysis, which is not only able to describe the first moment (Mean Acquisition Time, MAT), and the second moment (standard deviation

Marco Di Renzo; Luca Alfredo Annoni; Fabio Graziosi; Fortunato Santucci

2008-01-01

305

1448 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 27, NO. 11, JUNE 1, 2009 High-Chip-Count UWB Biphase Coding for  

E-print Network

of each user is well recognized. An effective two-user UWB-over-fiber system based on the DS advantages, such as immunity to multipath fading, extremely short-time duration, carrier-free, low-duty cycle to tens of meters. Such a short-range wireless network can operate mainly in indoor environments

Yao, Jianping

306

COMPACT ANTENNAS FOR UWB APPLICATIONS Taeyoung Yang, Seong-Youp Suh, Randall Nealy, William A. Davis, and Warren L. Stutzman  

E-print Network

COMPACT ANTENNAS FOR UWB APPLICATIONS Taeyoung Yang, Seong-Youp Suh, Randall Nealy, William A@vt.edu, stutzman@vt.edu Abstract-- This paper reports on an investigation of spherical, disc, and half-disc, Spherical antenna, Disc antenna, Half-disc antenna I. INTRODUCTION Since the United States Federal

Arslan, Hüseyin

307

2242 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 57, NO. 8, AUGUST 2009 UWB Elliptical Monopoles With a Reconfigurable  

E-print Network

-boat antenna presented in [8] and the fractal antenna proposed in [9]. Two open-circuit stubs were used in [102242 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 57, NO. 8, AUGUST 2009 UWB Elliptical-notch) characteristics in the frequency range between 5 and 6 GHz. The first antenna uses a 2 long, U-shaped slot

Tentzeris, Manos

308

Impact of Antennas on the Anchor-less Indoor Localization of a Static IR-UWB Pair  

E-print Network

, several solutions have been proposed for the Simultaneous Localization and Mapping (SLAM) problem (e.g. [7) technology (e.g. [2]) a relevant solution for joint short-range communication and localization. IndoorImpact of Antennas on the Anchor-less Indoor Localization of a Static IR-UWB Pair V. La Tosa, B

Paris-Sud XI, Université de

309

An analog approach to interference suppression in ultra-wideband receivers  

E-print Network

for OTAs in the bandpass filter. The loca- tion of the devices are labeled. . . . . . . . . . . . . . . . . . . . . . 66 50 Building block layout for OTAs in the bandpass filter. The orien- tation of the OTAs and CMFB circuitry are labeled... for OTAs in the bandpass filter. The loca- tion of the devices are labeled. . . . . . . . . . . . . . . . . . . . . . 66 50 Building block layout for OTAs in the bandpass filter. The orien- tation of the OTAs and CMFB circuitry are labeled...

Fischer, Timothy W.

2007-09-17

310

Energy-efficient analog-to-digital conversion for ultra-wideband radio  

E-print Network

In energy constrained signal processing and communication systems, a focus on the analog or digital circuits in isolation cannot achieve the minimum power consumption. Furthermore, in advanced technologies with significant ...

Ginsburg, Brian P. (Brian Paul), 1980-

2007-01-01

311

Investigation of ultra wideband multi-channel dichroic beamsplitters from 0.3 to 52 microns  

NASA Technical Reports Server (NTRS)

The development of a set of multi-channel dichroics which includes a 6 channel dichroic operating over the wavelength region from 0.3 to 52 microns is described. In order to achieve the optimum performance, the optical constraints of PbTe, Ge, and CdTe coatings in the strongly absorptive region have been determined by use of a new iterative method using normal incidence reflectance measurement of the multilayer together with initial values of energy gap and infinite refractive index for the semiconductor model. The design and manufacture of the dichroics is discussed and the final results are presented.

Zhang, K. Q.; Hunneman, R.; Seeley, J. S.; Hawkins, G. J.

1990-01-01

312

Ultra-wideband microwave photonic phase shifter with configurable amplitude response.  

PubMed

We introduce a new principle that enables separate control of the amplitude and phase of an optical carrier, simply by controlling the power of two stimulated Brillouin scattering (SBS) pumps. This technique is used to implement a microwave photonic phase shifter with record performance, which solves the bandwidth limitation of previous gain-transparent SBS-based phase shifters, while achieving unprecedented minimum power fluctuations, as a function of phase shift. We demonstrate 360° continuously tunable phase shift, with less than 0.25 dB output power fluctuations, over a frequency band from 1.5 to 31 GHz, limited only by the measurement equipment. PMID:25361102

Pagani, M; Marpaung, D; Eggleton, B J

2014-10-15

313

Power-efficient ultra wideband LNAs for the world's largest radio telescope  

NASA Astrophysics Data System (ADS)

This paper reports two Low Noise Amplifiers (LNA) for Aperture Array system of the international Square Kilometre Array (SKA) project. LNA design for SKA is a step change in traditional LNA design approach for radio astronomy applications as the defining aspects of performance are low noise along with low power consumption and adequate gain. The LNAs are designed, fabricated and characterised for frequency range of 20 -1000 MHz. One LNA has single ended input to single ended output configuration (LNA1) while the other LNA has balanced input to single ended output (LNA2). The S-parameter, noise figure (NF) and large signal response of the LNAs are measured at room temperature. Both LNAs show flat gain of higher than 30 dB over specified frequency range. Average NF values of LNA1 and LNA2 are 0.55 dB and 0.75 dB respectively. Mixed mode S-parameter response based on theoretical analysis of differential configuration is presented. The LNAs have exceptionally low power consumption of less than 25 mW; 20 times lower than the other reported LNAs available for the SKA and also covering complete frequency band with less than 1 dB NF. Therefore implication of these LNAs is a significant step forward as the projected number of LNAs required for the lower frequency band of SKA Aperture Array system is 5,600,000 (Dewdney et al., Proc. IEEE 97(8), 1482-1496, 2009; Faulkner et al. 2010).

Panahi, M.; Bhaumik, S.; George, D.

2014-10-01

314

Group delay in THz spectroscopy with ultra-wideband log-spiral antennae  

E-print Network

We report on the group delay observed in continuous-wave terahertz spectroscopy based on photomixing with phase-sensitive homodyne detection. We discuss the different contributions of the experimental setup to the phase difference \\Delta\\phi(\

Langenbach, M; Mayorga, I Cámara; Deninger, A; Thirunavukkuarasu, K; Hemberger, J; Grüninger, M

2014-01-01

315

Energy efficient ultra-wideband radio transceiver architectures and receiver circuits  

E-print Network

Energy efficient short-range radios have become an active research area with proliferation of portable electronics. A critical specification for radio efficiency is energy/bit. The FCC has allocated the 3.1-10.6 GHz band ...

Lee, Fred S. (Fred Shung-Neng), 1979-

2007-01-01

316

A framework for cooperative localization in ultra-wideband wireless networks  

E-print Network

Location-aware technologies have the potential to revolutionize computing, cellular services, sensor networks, and many other commercial, military, and social applications. In wireless networks, accurate information about ...

Lien, Jaime

2007-01-01

317

The National Geoelectromagnetic Facility - an open access resource for ultra wideband electromagnetic geophysics (Invited)  

NASA Astrophysics Data System (ADS)

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 units, increased instrument numbers, and concomitant developments in 3D/4D data interpretation. NSF Major Research Instrumentation support has been obtained to meet these requirements by developing an initial set of next-generation instruments as a National Geoelectromagnetic Facility (NGF), available to all PIs on a cost recovery basis, and operated by Oregon State University (OSU). In contrast to existing instruments with data acquisition systems specialized to operate within specific frequency bands and for specific electromagnetic methods, the NGF model "Zen/5" instruments being co-developed by OSU and Zonge Research and Engineering Organization are based on modular receivers with a flexible number of digital and analog input channels, designed to acquire EM data at dc, and from frequencies ranging from micro-Hz to MHz. These systems can be deployed in a compact, low power configuration for extended deployments (e.g. for crust-mantle scale experiments), or in a high frequency sampling mode for near surface work. The NGF is also acquiring controlled source EM transmitters, so that investigators may carry out magnetotelluric, audio-MT, radiofrequency-MT, as well as time-domain/transient EM and DC resistivity studies. The instruments are designed to simultaneously accommodate multiple electric field dipole sensors, magnetic fluxgates and induction coil sensors. Sample rates as high as 2.5 MHz with resolution between 24 and 32 bits, depending on sample rate, are specified to allow for high fidelity recording of waveforms. The NGF is accepting instrument use requests from investigators planning electromagnetic surveys via webform submission on its web site ngf.coas.oregonstate.edu. The site is also a port of entry to request access to the 46 long period magnetotelluric instruments also operated by OSU as national instrument pools. Cyberinfrastructure support is available to investigators, including field computers, EM data processing software, and access to a hybrid CPU-GPU parallel computing environment, currently configured with dual Intel Westmere hexacore CPUs and 960 NVidia Tesla and 1792 Nvidia Fermi GPU cores. The capabilities of the Zen/5 receivers will be presented, with examples of data acquired from a recent shallow water marine controlled source experiment conducted in coastal Oregon as part of an effort to locate a buried submarine pipeline, using a 1.1 KW 256 Hz signal source imposed on the pipeline from shore. A Zen/5 prototype instrument, modified for marine use through support by the Oregon Wave Energy Trust, demonstrated the marine capabilities of the NGF instrument design.

Schultz, A.; Urquhart, S.; Slater, M.

2010-12-01

318

An Ultra-Wideband Cross-Correlation Radiometer for Mesoscopic Experiments  

Microsoft Academic Search

We have designed, built and tested a cross-correlation radiometer for detecting statistical order in the quantum fluctuations of mesoscopic experiments at sub-Kelvin temperatures. Our system utilizes a fully analog front-end--operating over the X- and Ku-bands (8 to 18 GHz)--for computing the cross-correlation function. Digital signal processing techniques are used to provide robustness against instrumentation drifts and offsets. The economized version

Ryan Toonen; Cyrus Haselby; Hua Qin; Mark Eriksson; Robert Blick

2007-01-01

319

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

320

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

321

The Irregular-Shaped Fractal Antennas for Ultra Wideband Radio Systems  

Microsoft Academic Search

This paper proposes a novel design of a multiband fractal antenna of irregular shape using two-dimensional fractal clusters. The algorithm of generating fully reproducible fractal clusters is developed. The multiband behavior of the fractal-cluster based antennas is studied by means of numerical analysis. In comparison to regular-shaped fractal antennas more frequency bands and better matching are achieved. The spatial-frequency antenna

S. V. Krupenin; V. V. Kolesov; A. A. Potapov; N. G. Petrova

2006-01-01

322

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.

323

FALL STrUCTUrE, dYNAMiCS & FUNCTiON Mouse in-vivo MRI probe and proton RF coil for the UWB 900 MRI scanner.  

E-print Network

FALL STrUCTUrE, dYNAMiCS & FUNCTiON Figure 1. Mouse in-vivo MRI probe and proton RF coil for the UWB 900 MRI scanner. In vivo Mr imaging at 21.1 T Victor D. Schepkin, Samuel C. Grant and Timothy A imaging experiments using the Magnet lab world-record 900 uWB magnet. ExpEriMENTAL Testing the in vivo Mri

Weston, Ken

324

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

325

Radar cross section of the human heartbeat and respiration  

Microsoft Academic Search

This paper describes an experimental approach for finding the radar cross section (RCS) of human heartbeats and respiratory movements. A measurement setup, a calibration routine and required processing steps are presented. Using a 2-3GHz Ultra Wideband (UWB) radar, heartbeats and respiration of a human subject were recorded from a distance of 1.14m. Combining the recorded data to measurements with a

O. Aardal; Svein-Erik Hamran; T. Berger; J. Hammerstad; T. S. Lande

2010-01-01

326

Low-power integrated CMOS RF transceiver circuits for short-range applications  

Microsoft Academic Search

This paper discusses our efforts in designing different low-power RF transceiver blocks, starting with the LNA and power amplifier (PA). The paper discusses the effect of four different input matching methodologies on the gain of narrow-band LNAs. Measurement results of two LNAs fabricated in a 0.18 mum CMOS technology are also presented. Two ultra-wideband (UWB) LNA designs that aim for

M. Jamal Deen; Munir M. El-Desouki; Hamed M. Jafari; Saman Asgaran

2007-01-01

327

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

328

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

329

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. PMID:24971379

Islam, M. M.; Faruque, M. R. I.; Islam, M. T.

2014-01-01

330

Use of the Coupling Between Elements of the Vertical Antenna Array of LCRs to Gain Radiation Efficiency for UWB Pulses  

Microsoft Academic Search

The inductance of large current radiators (LCRs) can be reduced by stacking several of them as a vertical array. The reduced inductance permits a shorter rise time for the driving current. Both theory and experimental data show that the radiated field strengths are increased considerably for a fixed, small driving voltage.

Gennadiy P. Pochanin; Sergey A. Masalov

2007-01-01

331

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

332

UWB Band-notched Adjustable Antenna Using Concentric Split-ring Slots Structure  

NASA Astrophysics Data System (ADS)

In this paper, a kind of concentric split-ring slots structure is utilized to design a novel triple-band-notched UWB antenna. Firstly, a concentric split-ring slots structure that has a higher VSWR than that of a single slot at notch frequency is presented. What's more, the structure is very simple and feasible to obtain notched-band at different frequency by adjustment of the length of slot. Secondly, a triple-band-notched antenna, whose notched bands are at 3.52-3.81 GHz for WiMAX and 5.03-5.42 GHz and 5.73-56.17 GHz for WLAN, is designed by using this structure. At last, a compact size of 24 × 30 mm2 of the proposed antenna has been fabricated and measured and it is shown that the proposed antenna has a broadband matched impedance (3.05-14 GHz, VSWR < 2), relatively stable gain and good omnidirectional radiation patterns at low bands.

Yin, Y.; Hong, J. S.

2014-09-01

333

M-Sequence-Based Single-Chip UWB-Radar Sensor  

NASA Astrophysics Data System (ADS)

The article deals with a fully monolithically integrated single-chip M-sequence-based UWB-radar sensor, its architecture, selected design aspects and first measurement results performed on wafer and with packaged IC modules. The discussed chip is equipped with one transmitter and two receivers. The IC was designed and manufactured in commercially available high-performance 0.25 ?m SiGe BiCMOS technology (f t = 110 GHz). Due to the combination of fast digital and broadband analogue system blocks in one chip, special emphasis has been placed on the electrical isolation of these functional structures. The manufactured IC is enclosed in a low-cost QFN (quad flat-pack no-leads) package and mounted on a PCB permitting the creation of MIMO-sensor arrays by cascading a number of modules. In spite of its relatively high complexity, the sensor head features a compact design (chip size of 2 × 1 mm2, QFN package size 5 × 5 mm2) and moderate power consumption (below 1 W at -3 V supply). The assembled transceiver chip can handle signals in the frequency range from near DC up to 18 GHz. This leads to an impulse response (IRF) of FWHD ? 50 ps (full width at half duration).

Kmec, M.; Helbig, M.; Herrmann, R.; Rauschenbach, P.; Sachs, J.; Schilling, K.

334

A 112 Mb\\/s Full Duplex Remotely-Powered Impulse-UWB RFID Transceiver for Wireless NV-Memory Applications  

Microsoft Academic Search

A dual band symmetrical UWB-RFID transceiver for high capacity wireless NV-Memory applications is reported. The circuitexhibitsafigureofmeritof58pJ\\/band48pJ\\/binTxandRx respectively, with a 112.5 Mb\\/s data rate capability. It operates in the 7.9 GHz UWB frequency band for full duplex communication and is remotely powered through a UHF CW signal. The circuit has been implemented in a 0.13 m 1.2 V CMOS process. Index

Michael Pelissier; Joni Jantunen; Bertrand Gomez; Jarmo Arponen; Gilles Masson; Serigne Dia; Jaakko Varteva; Marjorie Gary

2011-01-01

335

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

336

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

337

Pulse stretcher  

DOEpatents

Apparatus for increasing the length of a laser pulse to reduce its peak power without substantial loss in the average power of the pulse is disclosed. The apparatus uses a White cell having a plurality of optical delay paths of successively increasing number of passes between the field mirror and the objective mirrors. A pulse from a laser travels through a multi-leg reflective path between a beam splitter and a totally reflective mirror to the laser output. The laser pulse is also simultaneously injected through the beam splitter to the input mirrors of the optical delay paths. The pulses from the output mirrors of the optical delay paths go simultaneously to the laser output and to the input mirrors of the longer optical delay paths. The beam splitter is 50% reflective and 50% transmissive to provide equal attenuation of all of the pulses at the laser output. 6 figures.

Horton, J.A.

1994-05-03

338

Pulse Voltammetry  

NASA Astrophysics Data System (ADS)

The idea of imposing potential pulses and measuring the currents at the end of each pulse was proposed by Barker in a little-known journal as early as in 1958 [1]. However, the first reliable trouble-free and affordable polarographs offering voltammetric pulse techniques appeared on the market only in the 1970s. This delay was due to some limitations on the electronic side. In the 1990s, again substantial progress in electrochemical pulse instrumentation took place. This was related to the introduction of microprocessors, computers, and advanced software.

Stojek, Zbigniew

339

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

340

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

341

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)

1994-01-01

342

A Parametric Analytical Diffusion Model for Indoor Ultra-Wideband Received Signal Majid A. Nemati Robert A. Scholtz  

E-print Network

be fine tuned to the environment Ã? Narrowband indoor fading channel is the special case of the proposed, reflected probably from different materials with unrelated reflection and absorption coefficients Ã? in the environment results in stronger reflections and higher probability of large innovation values ( ) tt d

Southern California, University of

343

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

344

Digital ADCs and ultra-wideband RF circuits for energy constrained wireless applications by Denis Clarke Daly.  

E-print Network

Ongoing advances in semiconductor technology have enabled a multitude of portable, low power devices like cellular phones and wireless sensors. Most recently, as transistor device geometries reach the nanometer scale, ...

Daly, Denis Clarke

2009-01-01

345

Short-Range Ultra-Wideband Systems UMass Antenna Lab USC UltRa Lab UC Berkeley BWRC  

E-print Network

(D.(D. GoeckelGoeckel, D., D. PozarPozar, D., D. SchaubertSchaubert)) #12;Short-Range Ultra: Break 10:45 AM: Antennas and Propagation Panel: Dan Schaubert, David Pozar, Won Namgoong, Bob Scholtz Pozar, Won Namgoong, Bob Scholtz, Anatoliy Boryssenko 12:00 PM: Lunch Break #12;Short-Range Ultra

Southern California, University of

346

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

347

A CPW-Fed Printed Loop Antenna for Ultra-Wideband Applications, and its Linear-Array Performance  

Microsoft Academic Search

A small CPW-fed loop antenna is described. The single antenna has a measured relative impedance bandwidth of 70%. Radiation patterns show stable co-polar and low cross-polar characteristics within the specified bandwidth. The small size of the radiator (0.5? at 13.6 GHz) makes it suitable for being used in linear-array applications. The linear-array performance of the antenna is investigated by means

F. M. Tanyer-Tigrek; I. E. Lager; Leonardus P. Ligthart

2010-01-01

348

Microwave and millimeter-wave rectifying circuit arrays and ultra-wideband antennas for wireless power transmission and communications  

E-print Network

In the future, space solar power transmission and wireless power transmission will play an important role in gathering clean and infinite energy from space. The rectenna, i.e., a rectifying circuit combined with an antenna, is one of the most...

Ren, Yu-Jiun

2009-05-15

349

CODE AIDED NEAR FULL RATE MULTIUSER TR-UWB SYSTEMS Zhengyuan Xu  

E-print Network

. The receiver yields sat- isfactory detection performance even in the presence of inter-pulse interference (IPI and can be maximally eliminated by statistical averaging, yielding a more purified waveform. During

Xu, Zhengyuan "Daniel"

350

Monolithically Integrated InP Wafer-Scale 100-Channel 10-GHz AWG and Michelson Interferometers for 1-THz-  

E-print Network

for 1-THz- Bandwidth Optical Arbitrary Waveform Generation F. M. Soares1 , J. H. Baek1 , N. K. Fontaine1 (OAWG) has potential applications such as: ultra-wideband wireless communications, pulsed radar, RF/THz-by-line Fourier spectral shaping to create arbitrary waveforms with a temporal resolution up to 5.1 THz [2

Kolner, Brian H.

351

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 ...

352

47 CFR 15.521 - Technical requirements applicable to all UWB devices.  

Code of Federal Regulations, 2012 CFR

...Operation onboard an aircraft, a ship or a satellite is prohibited. (b) Manufacturers...and a 1 millisecond or less averaging time. Unless otherwise stated, if pulse...15.503. The detection of tags or the transfer or data or voice information is not...

2012-10-01

353

47 CFR 15.521 - Technical requirements applicable to all UWB devices.  

Code of Federal Regulations, 2013 CFR

...Operation onboard an aircraft, a ship or a satellite is prohibited. (b) Manufacturers...and a 1 millisecond or less averaging time. Unless otherwise stated, if pulse...15.503. The detection of tags or the transfer or data or voice information is not...

2013-10-01

354

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.

355

Pulse News  

NSDL National Science Digital Library

It can be quite fun to read the news, but about what the beauty of viewing a clutch of colorful news sites? Pulse is an "elegant news reading application" designed for the iPhone, Android, and other mobile devices. The application uses colorful panning story bars and populates them with content from sources (such as CNN, the BBC, and so on) selected by the user. Visitors can sign up for a free account, and they will also want to read over the FAQ section on the site.

2012-02-03

356

Contemporary Wireless Technology  

NSDL National Science Digital Library

Wireless means radio in its broadest sense. However, in the early 21st century, wireless refers primarily to the two dominant forms of wireless: cell phones and wireless local area networks (WLANs). This module describes the idea behind the cellular telephone system, how it works, and the primary technologies used in the US and throughout the world. This module also introduces the wireless local area network or WLAN. WLANs are radio-linked computers that are part of a larger network. The wireless links make portability and mobility of computers possible. This module also briefly introduces four common forms of short- range wireless: Bluetooth, ZigBee, ultra wideband (UWB) and RFID.

2012-08-21

357

Multistatic adaptive pulse compression  

E-print Network

A new technique denoted as multistatic adaptive pulse compression (MAPC) is introduced which exploits recent work on adaptive pulse compression (APC) in order to jointly separate and pulse compress the concurrently received ...

Blunt, Shannon David; Gerlach, K.

2006-07-01

358

Fault tolerant pulse synchronization  

E-print Network

Pulse synchronization is the evolution of spontaneous firing action across a network of sensor nodes. In the pulse synchronization model all nodes across a network produce a pulse, or "fire", at regular intervals even without access to a shared...

Deconda, Keerthi

2009-05-15

359

Long pulse production from short pulses  

DOEpatents

A method of producing a long output pulse from a short pump pulse is disclosed, using an elongated amplified fiber having a doped core that provides an amplifying medium for light of one color when driven into an excited state by light of a shorter wavelength and a surrounding cladding. A seed beam of the longer wavelength is injected into the core at one end of the fiber and a pump pulse of the shorter wavelength is injected into the cladding at the other end of the fiber. The counter-propagating seed beam and pump pulse will produce an amplified output pulse having a time duration equal to twice the transit time of the pump pulse through the fiber plus the length of the pump pulse. 3 figs.

Toeppen, J.S.

1994-08-02

360

Long pulse production from short pulses  

DOEpatents

A method of producing a long output pulse (SA) from a short pump pulse (P), using an elongated amplified fiber (11) having a doped core (12) that provides an amplifying medium for light of one color when driven into an excited state by light of a shorter wavelength and a surrounding cladding 13. A seed beam (S) of the longer wavelength is injected into the core (12) at one end of the fiber (11) and a pump pulse (P) of the shorter wavelength is injected into the cladding (13) at the other end of the fiber (11). The counter-propagating seed beam (S) and pump pulse (P) will produce an amplified output pulse (SA) having a time duration equal to twice the transit time of the pump pulse (P) through the fiber (11) plus the length of the pump pulse (P).

Toeppen, John S. (Livermore, CA)

1994-01-01

361

Pulsed Zeeman spectroscopy  

E-print Network

Pulse from Stobotac 4. Upper Trace: Pulse from Pulse Generator Lower Trace: Pulse from Delay Line 5. Upper Trace: Voltage across 0. 787 Ohm Resistor Lower Trace: Output Voltage of Pulse Transformer Page 10 6. Pulse Coil Assembly 12 7. Temperature... an impedance of 0. 5 ohm to obtain highest power dis. , ipation. The pulse transformer as supplied vas modified by the addition of a 0. 787 ohm low inductance resistor made of flat nichrome ribbon. This resistor vas placed in series with the primary...

Cullen, Raymond Paul

2012-06-07

362

Reconfigurable RF-Waveform Generation Based on Incoherent-Filter Design  

Microsoft Academic Search

Radio-frequency (RF) waveform generators are key devices for a variety of applications, including radar, ultra-wideband communications, and electronic test measurements. Following advances in broadband coherent pulsed sources and pulse-shaping technologies, reconfigurable RF waveform generators operating at bandwidths >1 GHz have become a reality. In this work, we demonstrate reconfigurable RF waveform generation using broadband spectrally incoherent optical sources. This is

V. Torres; JesÚs Lancis; Pedro Andres; Lawrence R. Chen

2008-01-01

363

Third Sound Pulse Collisions  

NASA Astrophysics Data System (ADS)

We report measurements of third sound pulses in head-on collisions (K. S. Ketola, S. Wang, and R. B. Hallock, Physica B 194--196), 651 (1994). as a function of superfluid ^4He film thickness, pulse amplitude and pulse width for temperatures near 1.5 K. The substrate is a borosilicate glass slide with two Ag thermal drivers and an Al transition edge bolometer located halfway between the drivers. By generating one heating pulse from each driver separated by a selectable time delay, we can measure the profile of a collision with the bolometer, or we can cause the collision to occur between the bolometer and one of the drivers and observe the scattered third sound pulse. We explore collisions for a variety of conditions and show how the pulse interactions depend on the drive amplitudes. Measurements of single cooling pulses, cooling pulse collisions and heating pulses in an applied steady film flow will also be presented.

Hallock, R. B.; Lilly, M. P.

1996-03-01

364

Emerging Communication Technologies (ECT) Phase 3 Final 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.; Bates, Lakesha D.; Nelson, Richard A.

2004-01-01

365

Emerging Communication Technologies (ECT) Phase 2 Report. Volume 2; Appendices  

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

366

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

367

Random Noise Polarimetry Technique for Covert Detection of Targets Obscured by Foliage  

NASA Astrophysics Data System (ADS)

The University of Nebraska has been investigating a novel technique called random noise polarimetry for foliage penetration (FOPEN) imaging applications, under support from the US Air Force Office of Scientific Research (AFOSR). In this final report, we summarize the main activities and results of the research during the past three years (1999-2002). These include: (a) Development of an experimental UHF band ultra wideband (UWB) FOPEN noise radar system; (b) Development of a down range sidelobe suppression; (c) Study of the foliage transmission model and the impact of foliage obscuration; (d) Development of FOPEN SAR imaging model and image formation algorithms; (e) Study of the impact of frequency and aspect angle dependent target signatures on UWB SAR images; (f) Three-dimensional interferometric SAR and ISAR imaging techniques; (g) Development of SAR image enhancement techniques; and (h) Field tests, data acquisition and image processing using the experimental random noise radar system. Suggestions for future work are also presented.

Narayanan, Ram M.; Xu, Xiaojian; Henning, Joseph A.; Kumru, Cihan

2002-07-01

368

All-weather perception for small autonomous UGVs  

NASA Astrophysics Data System (ADS)

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 must be avoided (i.e. solid obstacles). In Phase I of this project, we demonstrated that UWB radar sensors can see through precipitation, smoke/fog, and foliage and detect solid obstacles. In Phase II, we are integrating all of these sensors with an iRobot PackBot. By the end of Phase II, we will demonstrate a fully-autonomous Daredevil PackBot that can avoid obstacles, build maps, and navigate to waypoints in all-weather conditions and through foliage.

Yamauchi, Brian

2008-04-01

369

Constant potential pulse polarography  

USGS Publications Warehouse

The new technique of constant potential pulse polarography, In which all pulses are to be the same potential, is presented theoretically and evaluated experimentally. The response obtained is in the form of a faradaic current wave superimposed on a constant capacitative component. Results obtained with a computer-controlled system exhibit a capillary response current similar to that observed In normal pulse polarography. Calibration curves for Pb obtained using a modified commercial pulse polarographic instrument are in good accord with theoretical predictions.

Christie, J.H.; Jackson, L.L.; Osteryoung, R.A.

1976-01-01

370

Optically pulsed electron accelerator  

DOEpatents

An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

Fraser, J.S.; Sheffield, R.L.

1985-05-20

371

Divided-pulse lasers.  

PubMed

We demonstrate the use of coherent division and recombination of the pulse within an ultrafast laser cavity to manage the nonlinear phase accumulation and scale the output pulse energy. We implement the divided-pulse technique in an ytterbium-doped fiber laser and achieve 16 times scaling of the pulse energy, to generate 6 nJ and 1.4 ps solitons in single-mode fiber. Potential extensions of this concept are discussed. PMID:24784100

Lamb, Erin S; Wright, Logan G; Wise, Frank W

2014-05-01

372

Divided-Pulse Lasers  

PubMed Central

We demonstrate the use of coherent division and recombination of the pulse within an ultrafast laser cavity to manage the nonlinear phase accumulation and scale the output pulse energy. We implement the divided-pulse technique in an ytterbium-doped fiber laser and achieve 16-times scaling of the pulse energy, to generate 6 nJ and 1.4 ps solitons in single mode fiber. Potential extensions of this concept are discussed. PMID:24784100

Lamb, Erin S.; Wright, Logan G.; Wise, Frank W.

2014-01-01

373

Laser pulse synthesis system  

US Patent & Trademark Office Database

A laser pulse synthesis system is provided. A further aspect of the present system uses a phase-only modulator to measure ultrashort laser pulses. An additional aspect achieves interferences between split subpulses even though the subpulses have different frequencies. Yet another aspect of a laser system employs multi-comb phase shaping of a laser pulse. In another aspect, a laser system includes pulse characterization and arbitrary or variable waveform generation through spectral phase comb shaping.

2014-03-18

374

Alternate drop pulse polarography  

USGS Publications Warehouse

The new technique of alternate drop pulse polarography is presented. An experimental evaluation of alternate drop pulse polarography shows complete compensation of the capacitative background due to drop expansion. The capillary response phenomenon was studied in the absence of faradaic reaction and the capillary response current was found to depend on the pulse width to the -0.72 power. Increased signal-to-noise ratios were obtained using alternate drop pulse polarography at shorter drop times.

Christie, J.H.; Jackson, L.L.; Osteryoung, R.A.

1976-01-01

375

The Discrete Pulse Transform  

Microsoft Academic Search

We investigate a recent algorithm, here called a discrete pulse transform (DPT), for the multiresolution analysis of a sequence. A DPT represents a sequence as a sum of pulses, where a pulse is a sequence which is zero everywhere except for a certain number of consecutive elements which have a constant nonzero value. Unlike the discrete Fourier and wavelet transforms,

C. H. Rohwer; D. P. Laurie

2006-01-01

376

UWB Localization Urban Applications  

E-print Network

-20 371.1 - Short Bursts ~ 1 msec - 511 Chips/Bit ~ 27 dB Processing Gain - 10-15 ft Accuracy = GPS Definition - Accurately locate (within 1-2 feet) a wireless network node in a harsh environment where GPS Miles Area · Options - GPS ­ Easy to Defeat & Spoof - E911 / AGPS / EOTD » Poor Accuracy ­ 150-350 ft

Southern California, University of

377

NETEX UWB test results  

Microsoft Academic Search

The goal of the Defense Advanced Research Projects Agency's (DARPA) Networking in Extreme Environments (NETEX) program is to create a wireless networking technology for the military user that enables robust connectivity in harsh environments and support its integration into new and emerging sensor and communication systems. Phase 1, resulted in a thorough understanding of the effects of ultra wide band

A. H. Light

2004-01-01

378

Micropower impulse radar technology and applications  

Microsoft Academic Search

The LLNL-developed Micropower Impulse Radar (MIR) technology has quickly gone from laboratory concept to embedded circuitry in numerous government and commercial systems in the last few years[l]. The main ideas behind MIR, invented by T. McEwan in the Laser Program, are the generation and detection systems for extremely low- power ultra-wideband pulses in the gigaHertz regime using low-cost components. These

J. Mast

1998-01-01

379

All-digital impulse radio for MUI\\/ISI-resilient multiuser communications over frequency-selective multipath channels  

Microsoft Academic Search

Impulse radio (IR) is an ultra-wideband system with attractive features for baseband asynchronous multiple access (MA), multimedia services, and tactical wireless communications. Implemented with analog components, the continuous-time IRMA model utilizes pulse-position modulation (PPM) and random time-hopping codes to alleviate multipath effects and suppress multiuser interference (MUI). We introduce a novel continuous-time multiple input multiple output (MIMO) PPM-IRMA scheme, and

Christophe J. Le Martret; Georgios B. Giannakis

2000-01-01

380

Dynamic pulse difference circuit  

Microsoft Academic Search

A digital electronic circuit of especial use for subtracting background activity pulses in gamma spectrometry comprises an up-down counter connected to count up with signal-channel pulses and to count down with background-channel pulses. A detector responsive to the count position of the up-down counter provides a signal when the up-down counter has completed one scaling sequence cycle of counts in

Gerald L

1978-01-01

381

Dynamic pulse difference circuit  

Microsoft Academic Search

A digital electronic circuit of especial use for subtracting background activity pulses in gamma spectrometry is disclosed which comprises an up-down counter connected to count up with signal-channel pulses and to count down with background-channel pulses. A detector responsive to the count position of the up-down counter provides a signal when the up-down counter has completed one scaling sequence cycle

1978-01-01

382

PulseSoar  

SciTech Connect

This paper is an introduction to the PulseSoar concept. PulseSoar is a hypervelocity airplane that uses existing airport facilities and current technologies to fly at the very edge of space. It will be shown that PulseSoar can fly between any two points on the globe in less than two hours with fuel efficiency exceeding current state of the art commercial airliners. In addition, it will be shown that PulseSoar avoids environmental issues concerning the ozone layer and sonic booms because of its unique flight profile. All of this can be achieved with current technology. PulseSoar does not require the development of enabling technology. It is a concept which can be demonstrated today. The importance of this idea goes beyond the technical significance`s of PulseSoar in terms of feasibility and performance. PulseSoar could provide a crucial economic advantage to America`s largest export market: commercial aircraft. PulseSoar is a breakthrough concept for addressing the emerging markets of long range and high speed aircraft. Application of PulseSoar to commercial transport could provide the US Aerospace industry a substantial lead in offering high speed/long range aircraft to the world`s airlines. The rapid emergence of a US developed high speed aircraft could also be important to our competitiveness in the Pacific Rim and South American economies. A quick and inexpensive demonstration vehicle is proposed to bang the concept to reality within two years. This discussion will address all the major technical subjects encompassed by PulseSoar and identifies several near-term, and low risk, applications which may be further explored with the initial demonstration vehicle. What is PulseSoar? PulseSoar could enable high speed, high altitude and long range flight without many of the difficulties encountered by traditional hypersonic vehicles.

Carter, P.; Peglow, S.

1992-07-21

383

Design, Modeling and Numerical Analysis of Microwave and Optical Devices: The Multi-band Patch Antenna, Ultra Wideband Ring Filter and Plasmonic Waveguide Coupler  

E-print Network

coupler validate the proposed idea imposing the corrugated waveguide as the photonic-to-plasmonic mode converter. Finally, it has to be clarified that, for the consideration of intellectual proprietary, some details of current undergoing researches...

Liu, Ya-Chi

2014-01-14

384

Critical pulse power components  

SciTech Connect

Critical components for pulsed power conditioning systems will be reviewed. Particular emphasis will be placed on those components requiring significant development efforts. Capacitors, for example, are one of the weakest elements in high-power pulsed systems, especially when operation at high-repetition frequencies for extended periods of time are necessary. Switches are by far the weakest active components of pulse power systems. In particular, opening switches are essentially nonexistent for most applications. Insulaton in all systems and components requires development and improvement. Efforts under way in technology base development of pulse power components will be discussed.

Sarjeant, W.J.; Rohwein, G.J.

1981-01-01

385

Pulsed Fission Propulsion Concept  

NASA Technical Reports Server (NTRS)

In the 1960's U.S. Government laboratories, under Project Orion, investigated a pulsed nuclear fission propulsion system. Small nuclear pulse units would be sequentially discharged from the aft end of the vehicle. A blast shield and shock absorber system would protect the crew and convert the shock loads into a continuous propusive force.

1999-01-01

386

Pulsed Fission Propulsion Concept  

NASA Technical Reports Server (NTRS)

In the 1960's U.S. Government laboratories, under Project Orion, investigated a pulsed nuclear fission propulsion system. Small nuclear pulse units would be sequentially discharged from the aft end of the vehicle. A blast shield and shock absorber system would protect the crew and convert the shock loads into a continuous propulsive force.

1999-01-01

387

The pulse sorting transform  

Microsoft Academic Search

A modification of conventional Fourier transforms is presented. This modification is called the pulse sorting transform (PST) and is useful in extracting information from signals comprised of interleaved pulse trains. A brief derivation of the PST from the conventional transform is presented, followed by theorems that describe the PST's properties. Several examples of how the PST can be an effective

K. C. Overman; D. F. Mix; J. A. Lookadoo

1990-01-01

388

Pulsed Laser Tissue Interaction  

NASA Astrophysics Data System (ADS)

Pulsed lasers, by virtue of their ability to deliver energy in a spatially and temporally confined fashion, are able to micromachine biological tissues. The clinical success of pulsed laser treatment, however, is often limited by the extent of damage that is caused to the tissue in the vicinity of the ablation crater. In general, pulsed ablation is a trade off between thermal damage to surrounding tissue, caused by relatively long pulses (>100 ms), and mechanical damage to surrounding tissue, caused by relatively short pulses (<1 ms). To identify the origin of pulsed laser induced damage, the possible laser tissue interactions and ablation are discussed here and in Chapter 14. The purpose of this chapter is to provide the reader with a condensed overview of the parameters that must be considered in the process of pulsed laser ablation of soft tissue. In this chapter, pulsed infrared ablation of biological soft tissue is used as a paradigm to illustrate the concepts and design considerations. Generally speaking, the absorption of laser light may lead to photothermal, photomechanical or photochemical interaction with the irradiated tissue [1-5]. The vast majority of therapeutic laser-tissue interactions is based on photothermal interactions where laser energy is converted into heat. Subsequent to thermalization of the absorbed optical energy, heat transfer mechanisms, in particular conduction allow thermal diffusion from high temperature areas to surrounding regions. When laser penetration depth is less than the laser spot radius, the thermal diffusion time, ? th, can be defined as:

Walsh, Joseph T.; van Leeuwen, Ton G.; Jansen, E. Duco; Motamedi, Massoud; Welch, Ashley J.

389

Bipolar pulse generator for intense pulsed ion beam accelerator  

NASA Astrophysics Data System (ADS)

A new type of pulsed ion beam accelerator named "bipolar pulse accelerator" (BPA) has been proposed in order to improve the purity of intense pulsed ion beams. To confirm the principle of the BPA, we developed a bipolar pulse generator for the bipolar pulse experiment, which consists of a Marx generator and a pulse forming line (PFL) with a rail gap switch on its end. In this article, we report the first experimental result of the bipolar pulse and evaluate the electrical characteristics of the bipolar pulse generator. When the bipolar pulse generator was operated at 70% of the full charge condition of the PFL, the bipolar pulse with the first (-138kV, 72ns) and the second pulse (+130kV, 70ns) was successfully obtained. The evaluation of the electrical characteristics indicates that the developed generator can produce the bipolar pulse with fast rise time and sharp reversing time.

Ito, H.; Igawa, K.; Kitamura, I.; Masugata, K.

2007-01-01

390

Chirped pulse Raman amplifier  

NASA Astrophysics Data System (ADS)

All modern terawatt- and petawatt-class laser systems are based on the principle of chirped-pulse amplification (CPA). In this work, a compact subsystem that shifts a micro-joule portion of the chirped pulse energy to a new wavelength outside its original bandwidth, then amplifies it to millijoule energy without adding pump lasers, and without compromising the output of the fundamental CPA system in any significant way, has been developed and integrated into a standard terawatt-class CPA system. In this chirped pulse Raman amplifier sub-system, a 30 mJ portion of a chirped 800 nm fundamental pulse within the CPA system was split into two unequal portions, each of which impinged on a Raman-active barium nitrate, or Ba(NO3)2, crystal of length 5 cm. The weaker portion created a weak (15 J) first Stokes pulse (873 nm) by Stimulated Raman Scattering (SRS) in the first crystal, which then seeded a non-collinear four-wave-mixing process driven by the stronger portion of the split-off CPA pulse in the second crystal. The latter process amplified the first Stokes seed pulse to several millijoules with excellent beam quality. A study of Raman gain as a function of time delay between pump and Stokes pulse in the second crystal revealed a sharply peaked narrow interval (˜3 ps FWHM) of high gain and a wider interval (˜50 ps) of low gain. The amplified, chirped first Stokes pulse was successfully compressed to 100 fs duration using a grating pair of different line density than in the main CPA system, based on a comprehensive dispersion analysis of the optical path of the first Stokes pulse. The possibility of generating higher-order Stokes and anti-Stokes sidebands of the CPA pulse is also demonstrated. Further amplification of the sideband pulse by conventional methods, using an additional pump laser, appears straightforward. The chirped pulse Raman amplifier provides temporally synchronized fundamental and Raman sideband pulses for performing two-color, high-intensity laser experiments, some of which are briefly discussed. It can be integrated into any standard CPA system, and provides significant new versatility for high-intensity laser sources.

Grigsby, Franklin Bhogaraju

391

Localized wave pulse experiments  

SciTech Connect

The Localized Wave project of the Strategic System Support Program has recently finished an experiment in cooperation with the Advanced SONAR group of the Applied Research Laboratory of the University of Texas at Austin. The purpose of the experiment was three-fold. They wanted to see if (1) the LW pulse could propagate over significant distances, to see if (2) a new type of array and drive system specifically designed for the pulse would increase efficiency over single frequency tone bursts, and to see if (3) the complexity of our 24 channel drivers resulted in better efficiency than a single equivalent pulse driving a piston. In the experiment, several LW pulses were launched from the Lake Travis facility and propagated over distances of either 100 feet or 600 feet, through a thermocline for the 600 foot measurements. The results show conclusively that the Localized Wave will propagate past the near field distance. The LW pulses resulted in extremely broad frequency band width pulses with narrow spatial beam patterns and unmeasurable side lobes. Their array gain was better than most tone bursts and further, were better than their equivalent piston pulses. This marks the first test of several Low Diffraction beams against their equivalent piston pulses, as well as the first propagation of LW pulses over appreciable distances. The LW pulse is now proven a useful tool in open water, rather than a laboratory curiosity. The experimental system and array were built by ARL, and the experiments were conducted by ARL staff on their standard test range. The 600 feet measurements were made at the farthest extent of that range.

Chambers, D L; Henderson, T L; Krueger, K L; Lewis, D K; Zilkowski, R N

1999-06-01

392

Digital pulse processing  

E-print Network

This thesis develops an exact approach for processing pulse signals from an integrate-and-fire system directly in the time-domain. Processing is deterministic and built from simple asynchronous finite-state machines that ...

McCormick, Martin (Martin Steven)

2012-01-01

393

Pulsed-neutron monochromator  

DOEpatents

In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The waves are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

Mook, H.A. Jr.

1984-01-01

394

Pulsed-neutron monochromator  

DOEpatents

In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The wave are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

Mook, Jr., Herbert A. (Oak Ridge, TN)

1985-01-01

395

Pulsed spallation neutron sources  

SciTech Connect

This paper reviews the early history of pulsed spallation neutron source development ar Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provide a few examples of applications in fundamental condensed matter physics, materials science and technology.

Carpenter, J.M. [Argonne National Lab., IL (United States). Intense Pulsed Neutron Source Div.

1996-05-01

396

PULSE COLUMN DESIGN  

Microsoft Academic Search

A stagewise approach was used in a theoretical analysis of pulse columns. ;\\u000a In the analysis the column was arbitrarily divided into discrete stages ;\\u000a comprising that part of the column between two adjacent perforated plates. The ;\\u000a operation of the pulse column was described mathematically using material balance ;\\u000a equations, and a design method was derived which used two

L. E. Burkhart; R. W. Fahien

1958-01-01

397

Micro pulse lidar  

Microsoft Academic Search

An eye safe, compact, solid-state lidar for profiling atmospheric cloud and aerosol scattering is described. The transmitter of the micro pulse lidar is a diode pumped microjoule pulse energy, high-repetition-rate Nd:YLF laser. Eye safety is obtained through beam expansion. The receiver uses a photon counting solid-state Geiger mode avalanche photodiode detector. Data acquisition is by a single card multichannel scaler.

J. D. Spinhirne

1993-01-01

398

LED flicker pulsing  

NASA Astrophysics Data System (ADS)

There is need to replace hazardous radioluminescent light sources with a means of illumination that is environmentally friendly. This paper describes an electronic source that was developed as a potential candidate to replace low intensity tritium in a military system. It employs an LED for illumination and a 3-volt coin cell battery as a power source. This new light source is electronically invisible, requires minimal maintenance, and provides the lowest practical illumination to preclude detection by optical means. The low intensity requires that the LED be driven at DC current levels resulting in poor luminous efficiency. Therefore, in an effort to maximize battery life, the LED is pulsed into a more optically efficient mode of operation. However, conventional pulsing techniques are not employed because of concerns the electronics could be identified by conspicuous power spectral density (PSD) components in the electromagnetic spectrum generated by a pulsed LED. Therefore, flicker noise concepts have been employed to efficiently drive the LED while generating a virtually undetectable spectral signature. Although ideally the pulse durations, magnitudes, and spacings should be random, a significant reduction in conspicuous PSD components can be achieved when imposing practical constraints. The dominant components of the power spectrum are significantly reduced using fixed pulse durations and magnitudes while varying only the pulse spacing. The mean duty cycle is set to provide the same effective illumination as DC operation while generating a PSD normally associated with natural phenomena.

Johnson, Mark A.; Cote, Paul J.

2001-08-01

399

Multihypothesis method in pulse deinterleaving  

Microsoft Academic Search

In the naval electronic environment, pulses emitted by radars are collected by electronic support measures receivers. The aim is to gather these pulses in such way that one cluster corresponds to one radar despite the waveform parameters agility. To achieve it, this paper describes a pulse train deinterleaving process using a multi-hypotheses architecture. A hypothesis tree, built from pulse measurements,

Cecile Brolly; Gerard Alengrin; Jean-Marc Lopez; Philippe F. Perez

1998-01-01

400

Pulse shaping with transmission lines  

DOEpatents

A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

Wilcox, R.B.

1985-08-15

401

Pulse shaping with transmission lines  

DOEpatents

A method and apparatus for forming shaped voltage pulses uses passive reflection from a transmission line with nonuniform impedance. The impedance of the reflecting line varies with length in accordance with the desired pulse shape. A high voltage input pulse is transmitted to the reflecting line. A reflected pulse is produced having the desired shape and is transmitted by pulse removal means to a load. Light activated photoconductive switches made of silicon can be utilized. The pulse shaper can be used to drive a Pockels cell to produce shaped optical pulses.

Wilcox, Russell B. (Oakland, CA)

1987-01-01

402

A case study on the feasibility and performance of an UWB-AoA real time location system for resources management of civil construction projects  

NASA Astrophysics Data System (ADS)

The application of integrated satellite and modern wireless positioning technologies for ubiquitous real-time resources management in large scale civil engineering projects can greatly optimize the time and cost in the construction process, and is now the trend for modern construction project management. As the outdoor conditions of most civil construction sites are open to sky, satellite positioning with the popularly used Global Positioning System (GPS) has been proved to be very efficient and effective. However, the condition in indoor and underground construction site is very complicated due to the fact that different construction activities would be carried out in different congested areas, involving heavy construction plant, equipment, professionals and technical personnel. Nowadays different emerging technologies such as Wi-Fi and ZigBee can be adopted for position and tracking in indoor environments. Nevertheless, under the very complicated construction site conditions these technologies may fail due to movement of human resources and construction plant, variation of metrological conditions, and serious multipath effects of signals. It is considered that Ultra Wide Band (UWB) technology is more suitable for indoor construction site environments. In this paper, a case study on the attempt of integrating GPS with Ubisense Real-time Location System (RTLS) for resources management in an underground railway construction site is discussed. Laboratory and field tests have shown that the RTLS can provide better resources management capability in terms of positioning accuracy and stability than Wi-Fi and ZigBee technologies under complicated construction environments. The test results show that the system can normally achieve better than 15 cm accuracy, and better than 1 m under adverse geometrical site condition. However, the high instrumental set up cost and the requirement for high quality data transmission cable for high precision time synchronization between sensors may deter wide application of similar system for resources management in construction sites.

Mok, Esmond; Xia, Linyuan; Retscher, Guenther; Tian, Hui

2010-06-01

403

Photoconductive circuit element pulse generator  

DOEpatents

A pulse generator for characterizing semiconductor devices at millimeter wavelength frequencies where a photoconductive circuit element (PCE) is biased by a direct current voltage source and produces short electrical pulses when excited into conductance by short laser light pulses. The electrical pulses are electronically conditioned to improve the frequency related amplitude characteristics of the pulses which thereafter propagate along a transmission line to a device under test.

Rauscher, Christen (Alexandria, VA)

1989-01-01

404

HydroPulse Drilling  

SciTech Connect

Tempress HydroPulse{trademark} tool increases overbalanced drilling rates by generating intense suction pulses at the drill bit. This report describes the operation of the tool; results of pressure drilling tests, wear tests and downhole drilling tests; and the business case for field applications. The HydroPulse{trademark} tool is designed to operate on weighted drilling mud at conventional flow rates and pressures. Pressure drilling tests confirm that the HydroPulse{trademark} tool provides 33% to 200% increased rate of penetration. Field tests demonstrated conventional rotary and mud motor drilling operations. The tool has been operated continuous for 50 hours on weighted mud in a wear test stand. This level of reliability is the threshold for commercial application. A seismic-while-drilling version of the tool was also developed and tested. This tool was used to demonstrate reverse vertical seismic profiling while drilling an inclined test well with a PDC bit. The primary applications for the HydroPulse{trademark} tool are deep onshore and offshore drilling where rate of penetration drives costs. The application of the seismic tool is vertical seismic profiling-while-drilling and look-ahead seismic imaging while drilling.

J.J. Kolle

2004-04-01

405

Pulse delay and pulse compression of ultrashort light pulses in tight focusing  

NASA Astrophysics Data System (ADS)

The tight focusing of radially polarized ultrashort pulsed laser beam is investigated, based on the Richards-Wolf vector diffraction theory. It is found that pulse delay phenomenon occurs near the focus. This is, near the focus, the ultrashort light pulse slows down. Meanwhile, with the decrease of the velocity the ultrashort pulsed laser beam is compressed in propagation direction. The space compression in propagation direction indicates that, though the pulse duration of the ultrashort light pulse does not change, the spatial pulse length of the ultrashort light pulse is reduced due to the pulse delay phenomenon. It is also shown that the different numerical aperture of the objective exhibits different velocity of the pulse light.

Lin, Huichuan; Chen, Ziyang; Pu, Jixiong

2014-12-01

406

Pulse shaping system  

DOEpatents

Temporally shaped electrical waveform generation provides electrical waveforms suitable for driving an electro-optic modulator (EOM) which produces temporally shaped optical laser pulses for inertial confinement fusion (ICF) research. The temporally shaped electrical waveform generation is carried out with aperture coupled transmission lines having an input transmission line and an aperture coupled output transmission line, along which input and output pulses propagate in opposite directions. The output electrical waveforms are shaped principally due to the selection of coupling aperture width, in a direction transverse to the lines, which varies along the length of the line. Specific electrical waveforms, which may be high voltage (up to kilovolt range), are produced and applied to the EOM to produce specifically shaped optical laser pulses. 8 figs.

Skeldon, M.D.; Letzring, S.A.

1999-03-23

407

Pulse shaping system  

DOEpatents

Temporally shaped electrical waveform generation provides electrical waveforms suitable for driving an electro-optic modulator (EOM) which produces temporally shaped optical laser pulses for inertial confinement fusion (ICF) research. The temporally shaped electrical waveform generation is carried out with aperture coupled transmission lines having an input transmission line and an aperture coupled output transmission line, along which input and output pulses propagate in opposite directions. The output electrical waveforms are shaped principally due to the selection of coupling aperture width, in a direction transverse to the lines, which varies along the length of the line. Specific electrical waveforms, which may be high voltage (up to kilovolt range), are produced and applied to the EOM to produce specifically shaped optical laser pulses.

Skeldon, Mark D. (Penfield, NY); Letzring, Samuel A. (Jemez Springs, NM)

1999-03-23

408

Pulse power linac  

DOEpatents

A linear acceleration for charged particles is constructed of a plurality of transmission line sections that extend between a power injection region and an accelerating region. Each line section is constructed of spaced plate-like conductors and is coupled to an accelerating gap located at the accelerating region. Each gap is formed between a pair of apertured electrodes, with all of the electrode apertures being aligned along a particle accelerating path. The accelerating gaps are arranged in series, and at the injection region the line sections are connected in parallel. At the injection region a power pulse is applied simultaneously to all line sections. The line sections are graduated in length so that the pulse reaches the gaps in a coordinated sequence whereby pulse energy is applied to particles as they reach each of the gaps along the accelerating path.

Villa, Francesco (Alameda, CA)

1990-01-01

409

Tunable THz pulse generation by optical rectification of ultrashort laser pulses with tilted pulse fronts  

Microsoft Academic Search

Optical rectification of ultrashort near-IR laser pulses with tilted pulse fronts and pulse energies of a few µJ in Mg-doped stoichiometric LiNbO 3 cooled to low temperature is a powerful technique for efficient generation of THz pulses. The pulse energy critically depends on the Mg doping (necessary for preventing photorefractive damage) and can be easily increased by a factor of

J. Hebling; A. G. Stepanov; G. Almási; B. Bartal; J. Kuhl

2004-01-01

410

Numerical validation of amorphous core pulse transformer  

Microsoft Academic Search

Pulse modulators generate high power pulses which are used for various industrial applications. This paper discusses the numerical validation of pulse transformer used in a pulse modulator wherein the pulse is created by switching on a capacitor in parallel to the pulse transformer using a solid state switch. The pulse transformer is connected to resistive load. The numerical validation was

H. P. Taskar; M. A. Dorlikar; M. H. Patil; H. A. Mangalvedekar; D. P. Chakravarthy

2010-01-01

411

Lectures on pulsed NMR  

SciTech Connect

These lectures discuss some recent developments in pulsed NMR, emphasizing fundamental principles with selected illustrative applications. Major topics covered include multiple-quantum spectroscopy, spin decoupling, the interaction of spins with a quantized field, adiabatic rapid passage, spin temperature and statistics of cross-polarization, coherent averaging, and zero field NMR. 32 refs., 56 figs.

Pines, A.

1988-08-01

412

Lectures on pulsed NMR  

SciTech Connect

These lectures discuss some recent developments in pulsed NMR, emphasizing fundamental principles with selected illustrative applications. Major topics covered include multiple-quantum spectroscopy, spin decoupling, the interaction of spins with a quantized field, adiabatic rapid passage, spin temperature and statistics of cross-polarization, coherent averaging, and zero field NMR. 55 figs.

Pines, A.

1986-09-01

413

Pulse-to-pulse correlation in satellite radar altimeters  

Microsoft Academic Search

Pulse-to-pulse correlation in satellite radar altimeters is examined to determine if range jitter in future altimeters could be reduced by increasing the pulse repetition frequency (PRF). Data from the Skylab radar altimeter is analyzed and compared with rules of thumb and the results of a Monte Carlo simulation. Altimeter range tracker configurations are reviewed and a simple curve is developed

Edward J. Walsh

1982-01-01

414

Pulse transformer R&D for NLC klystron pulse modulator  

Microsoft Academic Search

The authors have studied a conventional pulse transformer for the NLC klystron pulse modulator. The transformer has been analyzed using a simplified lumped circuit model. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and requires

M. Akemoto; S. Gold; Anatoly K Krasnykh; R F Koontz

1997-01-01

415

Development of the pulse transformer for NLC klystron pulse modulator  

Microsoft Academic Search

We have studied a conventional pulse transformer for the NLC klystron pulse modulator. The transformer has been analyzed using a simplified lumped circuit model. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and core size.

M. Akemoto; S. Gold; Anatoly K Krasnykh; R F Koontz

1997-01-01

416

Improvements in pulse transformer performance achieved using pulsed reset circuitry  

Microsoft Academic Search

The pulse transformer is ubiquitous in pulsed power application circuits including radar modulator circuits, particle accelerator circuits, and pulsed plasma implantation circuits. Traditionally these devices have been reset using a DC current source connected to the system via a reset inductor. The power required to reset the system in this manner depends on the resistance of the wire, the convenience

R. J. Adler; J. Stein; B. Ashcraft; R. J. Richter-Sand

1997-01-01

417

BLIND SYNCHRONIZATION IN MULTIUSER TRANSMIT-REFERENCE UWB Relja Djapic, Geert Leus, Antonio Trindade and Alle-Jan van der Veen  

E-print Network

. By recognizing that a shift in time corresponds to a phase rotation in the frequency domain, a blind synchro of a pulse as a reference or template to decode subsequent pulses leads to a simplified receiver on an efficient matching of the desired user code. This synchronization scheme allows for fast data ex- change

van der Veen, Alle-Jan

418

Two-Pulse Stitch Welding  

NASA Technical Reports Server (NTRS)

Second welding pulse at about 20 percent higher energy repairs bad single-pulse welds. Method used successfully to weld polytetrafluoroethyleneinsulated nickel wire to stainless-steel terminals in back-plane wiring.

Torborg, C. J.

1985-01-01

419

Sequentially pulsed traveling wave accelerator  

DOEpatents

A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

Caporaso, George J. (Livermore, CA); Nelson, Scott D. (Patterson, CA); Poole, Brian R. (Tracy, CA)

2009-08-18

420

White Paper Pulsed Antenna Measurements  

E-print Network

White Paper Agilent Pulsed Antenna Measurements Using PNA Network Analyzers #12;Abstract This paper is described. Measurements made using an Agilent E8360 PNA series Microwave Network Analyzer are presented of the pulsed RF signal spectrum, and will therefore measure the pulsed signal as though it were a CW signal. 2

del Barco, Enrique

421

Pulsed discharge helium ionization detector  

Microsoft Academic Search

A pulsed discharge helium ionization detector (PDHID) (patent pending) for gas chromatography has been developed. This detector uses a non-radioactive pulsed high voltage discharge source for generation of electrons and pulsed collection of these electrons. We have evaluated this detector for the analysis of a wide range of chemical compounds. In this paper the analytes are passed through the discharge

W. E. Wentworth; S. V. Vasnin; S. D. Stearns; C. J. Meyer

1992-01-01

422

Schedule-based sequential localization in asynchronous wireless networks  

NASA Astrophysics Data System (ADS)

In this paper, we consider the schedule-based network localization concept, which does not require synchronization among nodes and does not involve communication overhead. The concept makes use of a common transmission sequence, which enables each node to perform self-localization and to localize the entire network, based on noisy propagation-time measurements. We formulate the schedule-based localization problem as an estimation problem in a Bayesian framework. This provides robustness with respect to uncertainty in such system parameters as anchor locations and timing devices. Moreover, we derive a sequential approximate maximum a posteriori (AMAP) estimator. The estimator is fully decentralized and copes with varying noise levels. By studying the fundamental constraints given by the considered measurement model, we provide a system design methodology which enables a scalable solution. Finally, we evaluate the performance of the proposed AMAP estimator by numerical simulations emulating an impulse-radio ultra-wideband (IR-UWB) wireless network.

Zachariah, Dave; Angelis, Alessio De; Dwivedi, Satyam; Händel, Peter

2014-12-01

423

A 23 GHz low power VCO in SiGe BiCMOS technology  

NASA Astrophysics Data System (ADS)

A 23 GHz voltage controlled oscillator (VCO) with very low power consumption is presented. This paper presents the design and measurement of an integrated millimeter wave VCO. This VCO employs an on-chip inductor and MOS varactor to form a high Q resonator. The VCO RFIC was implemented in a 0.18 ?m 120 GHz ft SiGe hetero-junction bipolar transistor (HBT) BiCMOS technology. The VCO oscillation frequency is around 23 GHz, targeting at the ultra wideband (UWB) and short range radar applications. The core of the VCO circuit consumes 1 mA current from a 2.5 V power supply and the VCO phase noise was measured at around -94 dBc/Hz at a 1 MHz frequency offset. The FOM of the VCO is -177 dBc/Hz.

Yinkun, Huang; Danyu, Wu; Lei, Zhou; Fan, Jiang; Jin, Wu; Zhi, Jin

2013-04-01

424

Micro pulse laser radar  

NASA Astrophysics Data System (ADS)

An eye safe, compact, solid state lidar for profiling atmospheric cloud and aerosol scattering is disclosed. The transmitter of the micro pulse lidar is a diode pumped micro-J pulse energy, high repetition rate Nd:YLF laser. Eye safety is obtained through beam expansion. The receiver employs a photon counting solid state Geiger mode avalanche photodiode detector. Data acquisition is by a single card multichannel scaler. Daytime background induced quantum noise is controlled by a narrow receiver field-of-view and a narrow bandwidth temperature controlled interference filter. Dynamic range of the signal is limited to optical geometric signal compression. Signal simulations and initial atmospheric measurements indicate that micropulse lider systems are capable of detecting and profiling all significant cloud and aerosol scattering through the troposphere and into the stratosphere. The intended applications are scientific studies and environmental monitoring which require full time, unattended measurements of the cloud and aerosol height structure.

Spinhirne, James D.

1993-08-01

425

Micro pulse laser radar  

NASA Astrophysics Data System (ADS)

An eye safe, compact, solid state lidar for profiling atmospheric cloud and aerosol scattering is disclosed. The transmitter of the micro pulse lidar is a diode pumped micro-J pulse energy, high repetition rate Nd:YLF laser. Eye safety is obtained through beam expansion. The receiver employs a photon counting solid state Geiger mode avalanche photodiode detector. Data acquisition is by a single card multichannel scaler. Daytime background induced quantum noise is controlled by a narrow receiver field-of-view and a narrow bandwidth temperature controlled interference filter. Dynamic range of the signal is limited to optical geometric signal compression. Signal simulations and initial atmospheric measurements indicate that micropulse lider systems are capable of detecting and profiling all significant cloud and aerosol scattering through the troposphere and into the stratosphere. The intended applications are scientific studies and environmental monitoring which require full time, unattended measurements of the cloud and aerosol height structure.

Spinhirne, James

1992-08-01

426

Pulsed rf operation analysis  

SciTech Connect

The need for a very low final amplifier output impedance, always associated with class A operation, requires a very large power waste in the final tube. The recently suggested pulsed rf operation, while saving a large amount of power, increases the inherent final amplifier non linearity. A method is presented for avoiding the large signal non linear analysis and it is shown how each component of the beam induced voltage depends upon all the beam harmonics via some coupling coefficients which are evaluated.

Puglisi, M.; Cornacchia, M.

1981-01-01

427

Energy pulse bonding  

NASA Technical Reports Server (NTRS)

To eliminate many of the present termination problems a technique called energy pulse bonding (EPB) was developed. The process demonstrated the capability of: (1) joining conductors without prior removal of insulations, (2) joining conductors without danger of brittle intermetallics, (3) increased joint temperature capability, (4) simultaneous formation of several bonds, (5) capability of higher joint density, and (6) a production oriented process. The following metals were successfully bonded in the solid state: copper, beryllium copper, phosphor bronze, aluminum, brass, and Kovar.

Smith, G. C.

1972-01-01

428

High power pulsed lasers  

Microsoft Academic Search

Pulsed high power lasers can deliver sufficient energy on inertial fusion time scales (0.1–10 ns) to heat and compress DT fuel to fusion reaction conditions. Several laser systems have been examined for application to the fusion problem. Examples are Nd:glass, CO2, KrF, and I2, etc. A great deal of developmental effort has been applied to the Nd:glass laser and the

J. F. Holzrichter; D. Elimerl; E. V. George; J. B. Trenholme; W. W. Silnmons; J. T. Hunt

1982-01-01

429

Downhole pulse radar  

DOEpatents

A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole. 7 figs.

Chang, Hsi-Tien

1987-09-28

430

Downhole pulse radar  

DOEpatents

A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole.

Chang, Hsi-Tien (Albuquerque, NM)

1989-01-01

431

Pulsed thermionic converter study  

NASA Technical Reports Server (NTRS)

A nuclear electric propulsion concept using a thermionic reactor inductively coupled to a magnetoplasmadynamic accelerator (MPD arc jet) is described, and the results of preliminary analyses are presented. In this system, the MPD thruster operates intermittently at higher voltages and power levels than the thermionic generating unit. A typical thrust pulse from the MPD arc jet is characterized by power levels of 1 to 4 MWe, a duration of 1 msec, and a duty cycle of approximately 20%. The thermionic generating unit operates continuously but with a lower power level of approximately 0.4 MWe. Energy storage between thrust pulses is provided by building up a large current in an inductor using the output of the thermionic converter array. Periodically, the charging current is interrupted, and the energy stored in the magnetic field of the inductor is utilized for a short duration thrust pulse. The results of the preliminary analysis show that a coupling effectiveness of approximately 85 to 90% is feasible for a nominal 400 KWe system with an inductive unit suitable for a flight vehicle.

1976-01-01

432

Petawatt pulsed-power accelerator  

DOEpatents

A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load. When driven by LTD generators or other fast-pulse generators, the need for the pulse-forming circuits in the water section can be eliminated.

Stygar, William A. (Albuquerque, NM); Cuneo, Michael E. (Albuquerque, NM); Headley, Daniel I. (Albuquerque, NM); Ives, Harry C. (Albuquerque, NM); Ives, legal representative; Berry Cottrell (Albuquerque, NM); Leeper, Ramon J. (Albuquerque, NM); Mazarakis, Michael G. (Albuquerque, NM); Olson, Craig L. (Albuquerque, NM); Porter, John L. (Sandia Park, NM); Wagoner; Tim C. (Albuquerque, NM)

2010-03-16

433

High-speed pulse-shape generator, pulse multiplexer  

DOEpatents

The invention combines arbitrary amplitude high-speed pulses for precision pulse shaping for the National Ignition Facility (NIF). The circuitry combines arbitrary height pulses which are generated by replicating scaled versions of a trigger pulse and summing them delayed in time on a pulse line. The combined electrical pulses are connected to an electro-optic modulator which modulates a laser beam. The circuit can also be adapted to combine multiple channels of high speed data into a single train of electrical pulses which generates the optical pulses for very high speed optical communication. The invention has application in laser pulse shaping for inertial confinement fusion, in optical data links for computers, telecommunications, and in laser pulse shaping for atomic excitation studies. The invention can be used to effect at least a 10.times. increase in all fiber communication lines. It allows a greatly increased data transfer rate between high-performance computers. The invention is inexpensive enough to bring high-speed video and data services to homes through a super modem.

Burkhart, Scott C. (Livermore, CA)

2002-01-01

434

Pulsing electromagnetic fields induce cellular transcription  

Microsoft Academic Search

Weak, pulsing electromagnetic fields can modify biological processes. The hypothesis that responses to such induced currents depend on pulse characteristics was evaluated by using transcription as the target process. Two pulses in clinical use, the repetitive single pulse and the repetitive pulse train, were tested. These pulses produced different results from each other and from controls when transcription in dipteran

R. Goodman; C. A. Bassett; A. S. Henderson

1983-01-01

435

Pulse transformer R and D for NLC klystron pulse modulator  

SciTech Connect

The authors have studied a conventional pulse transformer for the NLC klystron pulse modulator. The transformer has been analyzed using a simplified lumped circuit model. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and requires a larger core size. After making a tradeoff among these parameters carefully, a conventional pulse transformer with a rise time of 250ns and a pulse droop of 3.6% has been designed and built. The transmission characteristics and pulse time-response were measured. The data were compared with the model. The agreement with the model was good when the measured values were used in the model simulation. The results of the high voltage tests using a klystron load are also presented.

Akemoto, M.; Gold, S.; Krasnykh, A.; Koontz, R.

1997-07-01

436

Development of the pulse transformer for NLC klystron pulse modulator  

SciTech Connect

We have studied a conventional pulse transformer for the NLC klystron pulse modulator. The transformer has been analyzed using a simplified lumped circuit model. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and core size. After making a tradeoff among these parameters carefully, a conventional pulse transformer with a rise time of 250ns and pulse droop of 3.6% has been designed and built. The transmission characteristics and pulse time-response were measured. The data were compared with the model. The agreement with the model was good when the measured values were used in the model simulation. The results of the high voltage tests are also presented.

Akemoto, M.; Gold, S.; Koontz, R.; Krasnykh, A.

1997-05-01

437

Coiled transmission line pulse generators  

DOEpatents

Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

McDonald, Kenneth Fox (Columbia, MO)

2010-11-09

438

Microwave and Pulsed Power  

SciTech Connect

The goals of the Microwave and Pulsed Power thrust area are to identify realizable research and development efforts and to conduct high-quality research in those pulse power and microwave technologies that support existing and emerging programmatic requirements at Lawrence Livermore National Laboratory (LLNL). Our main objective is to work on nationally important problems while enhancing our basic understanding of enabling technologies such as component design and testing, compact systems packaging, exploratory physics experiments, and advanced systems integration and performance. During FY-92, we concentrated our research efforts on the six project areas described in this report. (1) We are investigating the superior electronic and thermal properties of diamond that may make it an ideal material for a high-power, solid-state switch. (2) We are studying the feasibility of using advanced Ground Penetrating Imaging Radar technology for reliable non-destructive evaluation of bridges and other high-value concrete structures. These studies include conceptual designs, modeling, experimental verifications, and image reconstruction of simulated radar data. (3) We are exploring the efficiency of pulsed plasma processing techniques used for the removal of NO{sub x} from various effluent sources. (4) We have finished the investigation of the properties of a magnetically delayed low-pressure gas switch, which was designed here at LLNL. (5) We are applying statistical electromagnetic theory techniques to help assess microwave effects on electronic subsystems, by using a mode stirred chamber as our measurement tool. (6) We are investigating the generation of perfluoroisobutylene (PFIB) in proposed CFC replacement fluids when they are subjected to high electrical stresses and breakdown environments.

Freytag, E.K.

1993-03-01

439

Doubly resonant ultrachirped pulses  

E-print Network

Ultrachirped pulses for which the frequency chirp is of the order of the transition frequency of a two-level atom are examined. When the chirp is large enough, the resonance may be crossed twice, for positive and negative quadrature frequencies. In this scenario the analytic signal and quadrature decompositions of the field into amplitude and phase factors turn out to be quite different. The corresponding interaction pictures are strictly equivalent, but only as long as approximations are not applied. The domain of validity of the formal rotating wave approximation is dramatically enhanced using the analytic signal representation.

S. Ibáñez; A. Peralta Conde; D. Guéry-Odelin; J. G. Muga

2011-05-26

440

Ultrashort pulsed neutron source.  

PubMed

We report on a novel compact laser-driven neutron source with an unprecedented short pulse duration (<50??ps) and high peak flux (>10^{18}??n/cm^{2}/s), an order of magnitude higher than any existing source. In our experiments, high-energy electron jets are generated from thin (<3???m) plastic targets irradiated by a petawatt laser. These intense electron beams are employed to generate neutrons from a metal converter. Our method opens venues for enhancing neutron radiography contrast and for creating astrophysical conditions of heavy element synthesis in the laboratory. PMID:25396373

Pomerantz, I; McCary, E; Meadows, A R; Arefiev, A; Bernstein, A C; Chester, C; Cortez, J; Donovan, M E; Dyer, G; Gaul, E W; Hamilton, D; Kuk, D; Lestrade, A C; Wang, C; Ditmire, T; Hegelich, B M

2014-10-31

441

Pulsed Plasma Thruster Technology  

NASA Technical Reports Server (NTRS)

The continuing emphasis on reducing costs and downsizing spacecraft is forcing increased emphasis on reducing the subsystem mass and integration costs. For many commercial, scientific, and Department of Defense space missions, onboard propulsion is either the predominant spacecraft mass or it limits the spacecraft lifetime. Electromagnetic-pulsed-plasma thrusters (PPT's) offer the combined benefits of extremely low average electric power requirements (1 to 150 W), high specific impulse (approx. 1000 sec), and system simplicity derived from the use of an inert solid propellant. Potential applications range from orbit insertion and maintenance of small satellites to attitude control for large geostationary communications satellites.

1996-01-01

442

Pulsed ion beam source  

DOEpatents

An improved magnetically-confined anode plasma pulsed ion beam source. Beam rotation effects and power efficiency are improved by a magnetic design which places the separatrix between the fast field flux structure and the slow field structure near the anode of the ion beam source, by a gas port design which localizes the gas delivery into the gap between the fast coil and the anode, by a pre-ionizer ringing circuit connected to the fast coil, and by a bias field means which optimally adjusts the plasma formation position in the ion beam source.

Greenly, John B. (Lansing, NY)

1996-01-01

443

Green Light Pulse Oximeter  

DOEpatents

A reflectance pulse oximeter that determines oxygen saturation of hemoglobin using two sources of electromagnetic radiation in the green optical region, which provides the maximum reflectance pulsation spectrum. The use of green light allows placement of an oximetry probe at central body sites (e.g., wrist, thigh, abdomen, forehead, scalp, and back). Preferably, the two green light sources alternately emit light at 560 nm and 577 nm, respectively, which gives the biggest difference in hemoglobin extinction coefficients between deoxyhemoglobin, RHb, and oxyhemoglobin, HbO.sub.2.

Scharf, John Edward (Oldsmar, FL)

1998-11-03

444

Ultrashort Pulsed Neutron Source  

NASA Astrophysics Data System (ADS)

We report on a novel compact laser-driven neutron source with an unprecedented short pulse duration (<50 ps ) and high peak flux (>1018 n /cm2/s ), an order of magnitude higher than any existing source. In our experiments, high-energy electron jets are generated from thin (<3 ? m ) plastic targets irradiated by a petawatt laser. These intense electron beams are employed to generate neutrons from a metal converter. Our method opens venues for enhancing neutron radiography contrast and for creating astrophysical conditions of heavy element synthesis in the laboratory.

Pomerantz, I.; McCary, E.; Meadows, A. R.; Arefiev, A.; Bernstein, A. C.; Chester, C.; Cortez, J.; Donovan, M. E.; Dyer, G.; Gaul, E. W.; Hamilton, D.; Kuk, D.; Lestrade, A. C.; Wang, C.; Ditmire, T.; Hegelich, B. M.

2014-10-01

445

Pulsed quantum optomechanics  

PubMed Central

Studying mechanical resonators via radiation pressure offers a rich avenue for the exploration of quantum mechanical behavior in a macroscopic regime. However, quantum state preparation and especially quantum state reconstruction of mechanical oscillators remains a significant challenge. Here we propose a scheme to realize quantum state tomography, squeezing, and state purification of a mechanical resonator using short optical pulses. The scheme presented allows observation of mechanical quantum features despite preparation from a thermal state and is shown to be experimentally feasible using optical microcavities. Our framework thus provides a promising means to explore the quantum nature of massive mechanical oscillators and can be applied to other systems such as trapped ions. PMID:21900608

Vanner, M. R.; Pikovski, I.; Cole, G. D.; Kim, M. S.; Brukner, C.; Hammerer, K.; Milburn, G. J.; Aspelmeyer, M.

2011-01-01

446

Novel positioning system with extremely low power radio  

Microsoft Academic Search

In this paper, a concept of a novel UWB positioning system is presented, which satisfies the regulation for extremely low power radio systems in Japan. The spectrum mask of this regulation does not have deep notches unlike the ones for UWB systems. Therefore, the proposed UWB transmitter does not require a special pulse signal generator and a filter. The proposed

Yuichiro SHIMIZU; Yusuke TAKEUCHI; Yukitoshi SANADA

2004-01-01

447

Network-Centric Maritime Radiation Awareness and Interdiction Experiments: C2 Experimentation  

SciTech Connect

The paper addresses technological and operational challenges of developing a global plug-and-play Maritime Domain Security testbed for the Global War on Terrorism mission. This joint NPS-LLNL project is based on the NPS Tactical Network Topology (TNT) composed of long-haul OFDM networks combined with self-forming wireless mesh links to air, surface, ground, and underwater unmanned vehicles. This long-haul network is combined with ultra-wideband (UWB) communications systems for wireless communications in harsh radio propagation channels. LLNL's UWB communication prototypes are designed to overcome shortcomings of the present narrowband communications systems in heavy metallic and constricted corridors inside ships. In the center of our discussion are networking solutions for the Maritime Interdiction Operation (MIO) Experiments in which geographically distributed command centers and subject matter experts collaborate with the Boarding Party in real time to facilitate situational understanding and course of action selection. The most recent experiment conducted via the testbed extension to the Alameda Island exercised several key technologies aimed at improving MIO. These technologies included UWB communications from within the ship to Boarding Party leader sending data files and pictures, advanced radiation detection equipment for search and identification, biometric equipment to record and send fingerprint files to facilitate rapid positive identification of crew members, and the latest updates of the NPS Tactical Network Topology facilitating reachback to LLNL, Biometric Fusion Center, USCG, and DTRA experts.

Bordetsky, A; Dougan, A D; Nekoogar, F

2006-08-07

448

Heat driven pulse pump  

NASA Technical Reports Server (NTRS)

A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

Benner, Steve M (Inventor); Martins, Mario S. (Inventor)

2000-01-01

449

Bipolar pulse forming line  

DOEpatents

A bipolar pulse forming transmission line module for linear induction accelerators having first, second, third, fourth, and fifth planar conductors which form an interleaved stack with dielectric layers between the conductors. Each conductor has a first end, and a second end adjacent an acceleration axis. The first and second planar conductors are connected to each other at the second ends, the fourth and fifth planar conductors are connected to each other at the second ends, and the first and fifth planar conductors are connected to each other at the first ends via a shorting plate adjacent the first ends. The third planar conductor is electrically connectable to a high voltage source, and an internal switch functions to short a high voltage from the first end of the third planar conductor to the first end of the fourth planar conductor to produce a bipolar pulse at the acceleration axis with a zero net time integral. Improved access to the switch is enabled by an aperture through the shorting plate and the proximity of the aperture to the switch.

Rhodes, Mark A. (Pleasanton, CA)

2008-10-21

450

Compensated pulsed alternator  

DOEpatents

This invention relates to an electromechanical energy converter with inertial energy storage. The device, a single phase, two or multi-pole alternator with stationary field coils, and a rotating armature is provided. The rotor itself may be of laminated steel for slower pulses or for faster pulses should be nonmagnetic and electrically nonconductive in order to allow rapid penetration of the field as the armature coil rotates. The armature coil comprises a plurality of power generating conductors mounted on the rotor. The alternator may also include a stationary or counterrotating compensating coil to increase the output voltage thereof and to reduce the internal impedance of the alternator at the moment of peak outout. As the machine voltage rises sinusoidally, an external trigger switch is adapted to be closed at the appropriate time to create the desired output current from said alternator to an external load circuit, and as the output current passes through zero a self-commutating effect is provided to allow the switch to disconnect the generator from the external circuit.

Weldon, William F. (Austin, TX); Driga, Mircea D. (Austin, TX); Woodson, Herbert H. (Austin, TX)

1980-01-01

451

Pulsed Plasma Thruster Contamination  

NASA Technical Reports Server (NTRS)

Pulsed Plasma Thrusters (PPT's) are currently baselined for the Air Force Mightysat II.1 flight in 1999 and are under consideration for a number of other missions for primary propulsion, precision positioning, and attitude control functions. In this work, PPT plumes were characterized to assess their contamination characteristics. Diagnostics included planar and cylindrical Langmuir probes and a large number of collimated quartz contamination sensors. Measurements were made using a LES 8/9 flight PPT at 0.24, 0.39, 0.55, and 1.2 m from the thruster, as well as in the backflow region behind the thruster. Plasma measurements revealed a peak centerline ion density and velocity of approx. 6 x 10(exp 12) cm(exp -3) and 42,000 m/s, respectively. Optical transmittance measurements of the quartz sensors after 2 x 10(exp 5) pulses showed a rapid decrease in plume contamination with increasing angle from the plume axis, with a barely measurable transmittance decrease in the ultraviolet at 90 deg. No change in optical properties was detected for sensors in the backflow region.

Myers, Roger M.; Arrington, Lynn A.; Pencil, Eric J.; Carter, Justin; Heminger, Jason; Gatsonis, Nicolas

1996-01-01

452

Ultra-short pulse generator  

SciTech Connect

An inexpensive pulse generating circuit is disclosed that generates ultra-short, 200 picosecond, and high voltage 100 kW, pulses suitable for wideband radar and other wideband applications. The circuit implements a nonlinear transmission line with series inductors and variable capacitors coupled to ground made from reverse biased diodes to sharpen and increase the amplitude of a high-voltage power MOSFET driver input pulse until it causes non-destructive transit time breakdown in a final avalanche shockwave diode, which increases and sharpens the pulse even more.

McEwan, Thomas E. (Livermore, CA)

1993-01-01

453

Ultra-short pulse generator  

DOEpatents

An inexpensive pulse generating circuit is disclosed that generates ultra-short, 200 picosecond, and high voltage 100 kW, pulses suitable for wideband radar and other wideband applications. The circuit implements a nonlinear transmission line with series inductors and variable capacitors coupled to ground made from reverse biased diodes to sharpen and increase the amplitude of a high-voltage power MOSFET driver input pulse until it causes non-destructive transit time breakdown in a final avalanche shock wave diode, which increases and sharpens the pulse even more. 5 figures.

McEwan, T.E.

1993-12-28

454

Pulsed helium ionization detection system  

DOEpatents

A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

Ramsey, Roswitha S. (Knoxville, TN); Todd, Richard A. (Knoxville, TN)

1987-01-01

455

Pulsed helium ionization detection system  

DOEpatents

A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

Ramsey, R.S.; Todd, R.A.

1985-04-09

456

Population inversion by chirped pulses  

SciTech Connect

In this paper, we analyze the condition for complete population inversion by a chirped pulse over a finite duration. The nonadiabatic transition probability is mapped in the two-dimensional parameter space of coupling strength and detuning amplitude. Asymptotic forms of the probability are derived by the interference of nonadiabatic transitions for sinusoidal and triangular pulses. The qualitative difference between the maps for the two types of pulses is accounted for. The map is used for the design of stable inversion pulses under specific accuracy thresholds.

Lu Tianshi [Department of Mathematics and Statistics, Wichita State University, Wichita, Kansas 67260-0033 (United States)

2011-09-15

457

Plasma Energetic in Pulsed Laser Deposition and Pulsed Electron Deposition  

Microsoft Academic Search

Surface bombardment by energetic particles strongly affects thin film growth and allows surface processing under non-thermal equilibrium conditions. Deposition techniques enabling energy control can effectively manipulate the microstructure of the film and tune the resulting mechanical, electrical and optical properties. At the high power densities used for depositing stoichiometric films in the case pulsed ablation techniques such as Pulsed Laser

Solomon Kolagani

2009-01-01

458

Pulsed Plasma Accelerator Modeling  

NASA Technical Reports Server (NTRS)

This report presents the main results of the modeling task of the PPA project. The objective of this task is to make major progress towards developing a new computational tool with new capabilities for simulating cylindrically symmetric 2.5 dimensional (2.5 D) PPA's. This tool may be used for designing, optimizing, and understanding the operation of PPA s and other pulsed power devices. The foundation for this task is the 2-D, cylindrically symmetric, magnetohydrodynamic (MHD) code PCAPPS (Princeton Code for Advanced Plasma Propulsion Simulation). PCAPPS was originally developed by Sankaran (2001, 2005) to model Lithium Lorentz Force Accelerators (LLFA's), which are electrode based devices, and are typically operated in continuous magnetic field to the model, and implementing a first principles, self-consistent algorithm to couple the plasma and power circuit that drives the plasma dynamics.

Goodman, M.; Kazeminezhad, F.; Owens, T.

2009-01-01

459

Nanofabrication with Pulsed Lasers  

PubMed Central

An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3), is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser–matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics. PMID:20672069

2010-01-01

460

Pulsed hydrojet propulsion  

SciTech Connect

The pulsed hydrojet is a device in which the water ingested from the free stream is accelerated out of the exhaust pipe to produce thrust. In this report we describe and analyze a way of accelerating the stream of water with pockets of high pressure steam and gas generated inside the stream by an exothermal reaction of suitable propellant injected and dispersed in the water. The velocity increment that must be imparted to the water to produce a substantial thrust need not be very large because the density of the water is comparable to the average density of the accelerated body. Results of the numerical modeling of the proposed jet acceleration mechanism indicate that the hydrojet propulsion device is potentially capable of propelling underwater projectiles at speeds three to five times greater than those currently attainable. Several promising applications of the hydrojet thruster are discussed and evaluated.

Bohachevsky, I.O.; Torrey, M.D.

1985-01-01

461

Generating Independent Preionizing Pulses for Lasers  

NASA Technical Reports Server (NTRS)

Simple pulse-coupling winding on saturable reactor core lets core act as pulse transformer, passing preionizing pulse from winding to tapered transmission line, then to laser. Laser prepared for independent firing pulse, which follows preionizing pulse. Winding is simple, light in weight, low in bulk and power consumption, and inexpensive.

Pacala, T. J.

1986-01-01

462

Rotating machines for pulsed power  

Microsoft Academic Search

The requirement for more compact pulsed power sources is increasing in response to a broad range of pulsed and intermittent duty electric weapon systems currently under development. Electromagnetic launchers, aircraft catapults, directed energy systems including microwave sources and electric lasers, and electric armors all require high energies delivered intermittently at very high power. Power systems that can provide both compact

W. A. Walls

2002-01-01

463

Modern Pulsed Fission Propulsion Concept  

NASA Technical Reports Server (NTRS)

In the 1960's U.S. Government laboratories, under Project Orion, investigated a pulsed nuclear fission propulsion system. Based on Project Orion, an interplanetary vehicle using pulsed fission propulsion would incorporate modern technologies for momentum transfer, thermal management, and habitation design.

1999-01-01

464

Luminous pulses during triggered lightning  

NASA Astrophysics Data System (ADS)

A triggered lightning flash that transferred negative charge to ground in central New Mexico produced more than three levels of branching above the main channel to ground in a 1 km vertical field of view. A high-speed video recording shows that the main channel had about 50 brief luminous pulses, many of which were superimposed on a slowly changing persistent luminosity. In contrast, superposition was rare in the uppermost visible branches because luminous pulses first appeared on preexisting dark channels before merging into a luminous channel. This observation suggests that luminous pulses in triggered and natural lightning originate only on dark branches and that the complexity of the main channel to ground is the result of multiple mergers of dark branches with pulses into luminous branches without pulses. This suggestion is contrary to an earlier conclusion that there are two kinds of luminous pulses. We also observe behavior characteristic of electromagnetic waves on transmission lines: when a downward propagating luminous pulse reaches a junction with another initially dark branch, it travels both upward and downward along that branch. Upon reaching the ground the downward propagating wave produces a bright reflection which also splits at the junctions, producing luminosity for a short distance upward in one direction while propagating much farther upward along the path charged by the downward propagating wave. However, when a downward moving luminous pulse reaches a junction with an initially luminous branch, splitting is not evident, probably due to the greater conductivity of the luminous channel.

Winn, W. P.; Eastvedt, E. M.; Trueblood, J. J.; Eack, K. B.; Edens, H. E.; Aulich, G. D.; Hunyady, S. J.; Murray, W. C.

2012-05-01

465

All about Heart Rate (Pulse)  

MedlinePLUS

All About Heart Rate (Pulse) Updated:Sep 30,2014 What should you know about your heart rate? Even if you’re not an athlete, ... Where is it and what is a normal heart rate? The best places to find your pulse ...

466

Precision digital pulse phase generator  

DOEpatents

A timing generator comprises a crystal oscillator connected to provide an output reference pulse. A resistor-capacitor combination is connected to provide a variable-delay output pulse from an input connected to the crystal oscillator. A phase monitor is connected to provide duty-cycle representations of the reference and variable-delay output pulse phase. An operational amplifier drives a control voltage to the resistor-capacitor combination according to currents integrated from the phase monitor and injected into summing junctions. A digital-to-analog converter injects a control current into the summing junctions according to an input digital control code. A servo equilibrium results that provides a phase delay of the variable-delay output pulse to the output reference pulse that linearly depends on the input digital control code.

McEwan, Thomas E. (Livermore, CA)

1996-01-01

467

Precision digital pulse phase generator  

DOEpatents

A timing generator comprises a crystal oscillator connected to provide an output reference pulse. A resistor-capacitor combination is connected to provide a variable-delay output pulse from an input connected to the crystal oscillator. A phase monitor is connected to provide duty-cycle representations of the reference and variable-delay output pulse phase. An operational amplifier drives a control voltage to the resistor-capacitor combination according to currents integrated from the phase monitor and injected into summing junctions. A digital-to-analog converter injects a control current into the summing junctions according to an input digital control code. A servo equilibrium results that provides a phase delay of the variable-delay output pulse to the output reference pulse that linearly depends on the input digital control code. 2 figs.

McEwan, T.E.

1996-10-08

468

Pre-earthquake Magnetic Pulses  

E-print Network

A semiconductor model of rocks is shown to describe unipolar magnetic pulses, a phenomenon that has been observed prior to earthquakes. These pulses are observable because their extremely long wavelength allows them to pass through the Earth's crust. Interestingly, the source of these pulses may be triangulated to pinpoint locations where stress is building deep within the crust. We couple a semiconductor drift-diffusion model to a magnetic field in order to describe the electromagnetic effects associated with electrical currents flowing within rocks. The resulting system of equations is solved numerically and it is seen that a volume of rock may act as a diode that produces transient currents when it switches bias. These unidirectional currents are expected to produce transient unipolar magnetic pulses similar in form, amplitude, and duration to those observed before earthquakes, and this suggests that the pulses could be the result of geophysical semiconductor processes.

Scoville, John; Freund, Friedemann

2014-01-01

469

Square pulse linear transformer driver  

NASA Astrophysics Data System (ADS)

The linear transformer driver (LTD) technological approach can result in relatively compact devices that can deliver fast, high current, and high-voltage pulses straight out of the LTD cavity without any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The usual LTD architecture [A. A. Kim, M. G. Mazarakis, V. A. Sinebryukhov, B. M. Kovalchuk, V. A. Vizir, S. N Volkov, F. Bayol, A. N. Bastrikov, V. G. Durakov, S. V. Frolov, V. M. Alexeenko, D. H. McDaniel, W. E. Fowler, K. LeCheen, C. Olson, W. A. Stygar, K. W. Struve, J. Porter, and R. M. Gilgenbach, Phys. Rev. ST Accel. Beams 12, 050402 (2009)PRABFM1098-440210.1103/PhysRevSTAB.12.050402; M. G. Mazarakis, W. E. Fowler, A. A. Kim, V. A. Sinebryukhov, S. T. Rogowski, R. A. Sharpe, D. H. McDaniel, C. L. Olson, J. L. Porter, K. W. Struve, W. A. Stygar, and J. R. Woodworth, Phys. Rev. ST Accel. Beams 12, 050401 (2009)PRABFM1098-440210.1103/PhysRevSTAB.12.050401] provides sine shaped output pulses that may not be well suited for some applications like z-pinch drivers, flash radiography, high power microwaves, etc. A more suitable power pulse would have a flat or trapezoidal (rising or falling) top. In this paper, we present the design and first test results of an LTD cavity that generates such a type of output pulse by including within its circular array a number of third harmonic bricks in addition to the main bricks. A voltage adder made out of a square pulse cavity linear array will produce the same shape output pulses provided that the timing of each cavity is synchronized with the propagation of the electromagnetic pulse.

Kim, A. A.; Mazarakis, M. G.; Sinebryukhov, V. A.; Volkov, S. N.; Kondratiev, S. S.; Alexeenko, V. M.; Bayol, F.; Demol, G.; Stygar, W. A.

2012-04-01

470

Covert communications using random noise signals: effects of atmospheric propagation nulls and rain  

NASA Astrophysics Data System (ADS)

In military communications, there exist numerous potential threats to message security. Ultra-wideband (UWB) signals provide secure communications because they cannot, in general, be detected using conventional receivers and they can be made relatively immune from jamming. The security of an UWB signal can be further improved by mixing it with random noise. By using a random noise signal, the user can conceal the message signal within the noise waveform and thwart detection by hostile forces. This paper describes a novel spread spectrum technique that can be used for secure and covert communications. The technique is based on the use of heterodyne correlation techniques to inject coherence in a random noise signal. The modulated signal to be transmitted containing the coherent carrier is mixed with a sample of an ultra-wideband (UWB) random noise signal. The frequency range of the UWB noise signal is appropriately chosen so that the lower sideband of the mixing process falls over the same frequency range. Both the frequency-converted noise-like signal and the original random noise signal are simultaneously transmitted on orthogonally polarized channels through a dual-polarized transmitting antenna. The receiver consists of a similar dual-polarized antenna that simultaneously receives the two orthogonally polarized transmitted signals, amplifies each in a minimum phase limiting amplifier, and mixes these signals in a double sideband upconverter. The upper sideband of the mixing process recovers the modulated signal, which can then be demodulated. The advantage of this technique lies in the relative immunity of the random noise-like unpolarized transmit signal from detection and jamming. Since the transmitted signal "appears" totally unpolarized and noise-like, linearly polarized receivers are unable to identify, decode, or otherwise extract useful information from the signal. The system is immune from interference caused by high power linearly polarized signal transmissions since these signals are rejected during the correlation process at the receiver. Dispersive effects caused by the atmosphere and other factors are significantly reduced since both polarization channels operate over identical frequency bands. This paper analyzes in detail various atmospheric propagation effects such as nulls, rain, and forests.

Mohan, Karen M.; Narayanan, Ram M.

2005-06-01

471

Pulse Train Generator for Producing Odd or Even Number of Pulses with Variable Pulse Spacing.  

National Technical Information Service (NTIS)

The pulse train generator is for use in computer circuitry. In the basic embodiment there is a plurality of monostable multivibrators and an odd number of pulses are generated for each trigger signal. The structure in a second embodiment is the same in th...

M. F. Williams, A. F. Thornhill

1965-01-01

472

Residual stress reduction by combined treatment of pulsed magnetic field and pulsed current  

Microsoft Academic Search

This paper reports a significant decrease on residual stress by combined treatment of a pulsed magnetic field and a pulse current on steel samples with pre-induced residual stress conditions, compared to a separately single treatment by either the pulsed magnetic field or the pulsed current. Briefly, 10% stress decrease by pulsed magnetic field treatment and 20% increase by pulsed current

zhipeng Cai; Xinquan Huang

2011-01-01

473

Spectral line-by-line pulse shaping for optical arbitrary pulse-train generation  

E-print Network

. Discrete pulse train packets (or bursts) have been generated by both Fourier transform pulse shapers [2-train generation also using a Fourier transform pulse shaper but in the group of lines pulse-shaping regime [2 of short periodic input pulses with our Fou- rier transforms line-by-line pulse shaper. Suppose

Purdue University

474

Count rate limitations in pulsed accelerator fields  

SciTech Connect

This paper discusses various concepts involved in the counting losses of pulse-counting health physics instrumentation when used within the pulsed radiation environments of typical accelerator fields, in order to pre-establish appropriate limitations in use. Discussed are the 'narrow' pulse and the 'wide' pulse cases, the special effect of neutron moderating assemblies, and the effect of pulse microstructure on the counting losses of the pulse-counting instrumentation. Examples are provided which highlight the various concepts and limitations.

Justus, Alan L [Los Alamos National Laboratory

2010-12-15

475

High-power microwave pulse generator  

Microsoft Academic Search

An inexpensive alternative to commercial high-power microwave pulse generators is described. The present high-power microwave pulse generator utilizes a surplus MIT model 3 Mark II hard tube modulator and 2J51 magnetron. The basic design and technical details of the pulse generator are presented. The pulse generator is designed to produce 8.5–9.6 GHz pulses with pulse lengths ranging from 2 to

G. O. White; L. Chen; C. E. Patton; R. L. Tinkoff

1992-01-01

476

High-power microwave pulse generator  

Microsoft Academic Search

An inexpensive alternative to commercial high-power microwave-pulse generators is described. The present high-power microwave-pulse generator utilizes a surplus MIT model-3 Mark-II hard-tube modulator and 2J51 magnetron. The basic design and technical details of the pulse generator are presented. The pulse generator is designed to produce 8.5-9.6 GHz pulses with pulse lengths ranging from 2 to 4 microns with a nominal

G. O. White; L. Chen; C. E. Patton; R. L. Tinkoff

1992-01-01

477

Bomb Pulse Biology  

PubMed Central

The past decade has seen an explosion in use of the 14C bomb-pulse to do fundamental cell biology. Studies in the 1960’s used decay counting to measure tissue turnover when the atmospheric 14C/C concentration was changing rapidly. Today bulk tissue measurements are of marginal interest since most of the carbon in the tissue resides in proteins, lipids and carbohydrates that turn over rapidly. Specific cell types with specialized functions are the focus of cell turnover investigations. Tissue samples need to be fresh or frozen. Fixed or preserved samples contain petroleum-derived carbon that has not been successfully removed. Cell or nuclear surface markers are used to sort specific cell types, typically by fluorescence-activated cell sorting (FACS). Specific biomolecules need to be isolated with high purity and accelerator mass spectrometry (AMS) measurements must accommodate samples that generally contain less than 40 micrograms of carbon. Furthermore, all separations must not add carbon to the sample. Independent means such as UV absorbance must be used to confirm molecule purity. Approaches for separating specific proteins and DNA and combating contamination of undesired molecules are described. PMID:23359559

Sarachine Falso, Miranda J.; Buchholz, Bruce A.

2012-01-01

478

Bomb pulse biology  

NASA Astrophysics Data System (ADS)

The past decade has seen an explosion in use of the 14C bomb pulse to do fundamental cell biology. Studies in the 1960s used decay counting to measure tissue turnover when the atmospheric 14C/C concentration was changing rapidly. Today bulk tissue measurements are of marginal interest since most of the carbon in the tissue resides in proteins, lipids and carbohydrates that turn over rapidly. Specific cell types with specialized functions are the focus of cell turnover investigations. Tissue samples need to be fresh or frozen. Fixed or preserved samples contain petroleum-derived carbon that has not been successfully removed. Cell or nuclear surface markers are used to sort specific cell types, typically by fluorescence-activated cell sorting (FACS). Specific biomolecules need to be isolated with high purity and accelerator mass spectrometry (AMS) measurements must accommodate samples that generally contain less than 40 ?g of carbon. Furthermore, all separations must not add carbon to the sample. Independent means such as UV absorbance must be used to confirm molecule purity. Approaches for separating specific proteins and DNA and combating contamination of undesired molecules are described.

Falso, Miranda J. Sarachine; Buchholz, Bruce A.

2013-01-01

479

Magnetic Alignment of Pulsed Solenoids Using the Pulsed Wire Method  

SciTech Connect

A unique application of the pulsed-wire measurement method has been implemented for alignment of 2.5 T pulsed solenoid magnets. The magnetic axis measurement has been shown to have a resolution of better than 25 {micro}m. The accuracy of the technique allows for the identification of inherent field errors due to, for example, the winding layer transitions and the current leads. The alignment system is developed for the induction accelerator NDCX-II under construction at LBNL, an upgraded Neutralized Drift Compression experiment for research on warm dense matter and heavy ion fusion. Precise alignment is essential for NDCX-II, since the ion beam has a large energy spread associated with the rapid pulse compression such that misalignments lead to corkscrew deformation of the beam and reduced intensity at focus. The ability to align the magnetic axis of the pulsed solenoids to within 100 pm of the induction cell axis has been demonstrated.

Arbelaez, D.; Madur, A.; Lipton, T.M.; Waldron, W.L.; Kwan, J.W.

2011-04-01

480

Step piston pulse tube refrigerator  

NASA Astrophysics Data System (ADS)

In this paper, a numerical simulation is done for a step piston pulse tube refrigerator. The step piston pulse tube refrigerator is a modification of an inertance tube pulse tube refrigerator, which has a step piston compressor. The step piston in a step cylinder forms a compression space which is connected to the after cooler and an expansion space which is connected to the buffer. Numerical simulation shows that it is more effective at higher refrigeration temperature. It also shows there is an optimum swept volume ratio of the expansion space over the compression space, and an optimum diameter and length of the inertance tube for a given refrigerator.

Zhu, Shaowei

2014-11-01

481

High pressure pulsed capillary viscometry  

NASA Technical Reports Server (NTRS)

An analytical and test program was conducted in order to establish the feasibility of a multichamber pulsed-capillary viscometer. The initial design incorporated a piston, ram, and seals which produced measured pulses up to 30,000 psi in the closed chamber system. Pressure pulses from one to ten milliseconds were investigated in a system volume of 1 cuin. Four test fluids: a MIL-L-7808, a 5P4E polyphenyl ether, a MIL-L-23699A, and a synthetic hydrocarbon were examined in the test pressure assembly. The pressure-viscosity coefficient and viscosity delay time were determined for the MIL-L-7808 lubricant tested.

Smith, R. L.; Walowitt, J. A.; Pan, C. H. T.

1972-01-01

482

Preliminary study of pulsed powering  

NASA Astrophysics Data System (ADS)

The standard solution for powering the electronics of particle physics detectors is to supply direct current. In this report, we investigate several advantages of using a Pulsed Powering scheme. Pulsed Powering could achieve 2-wire, point-of-load voltage regulation over typical low voltage power cables. This could be a reliable and serviceable solution for point of load voltage regulation in the high radiation environment of the High Luminosity Large Hadron Collider. Pulsed Powering might also be exploited to provide an inexpensive solution for the elimination of voltage offsets among ATLAS Pixel Detector subsystems and offer new low mass techniques for distributing power to particle detectors.

Hasib, A.; Boyd, R.; Gutierrez, P.

2014-01-01

483

Hyper dispersion pulse compressor for chirped pulse amplification systems  

DOEpatents

A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.

Barty, Christopher P. J. (Hayward, CA)

2011-11-29

484

Plasma Energetics in Pulsed Laser and Pulsed Electron Deposition  

Microsoft Academic Search

Surface bombardment by energetic particles strongly affects thin-film growth and allows surface processing under non-thermal-equilibrium conditions. Deposition techniques enabling energy control can effectively manipulate the microstructure of the film and tune the resulting mechanical, electrical, and optical properties. At the high power densities used for depositing stoichiometric films in the case of pulsed ablation techniques such as pulsed laser deposition

Mikhail D. Strikovski; Jeonggoo Kim; Solomon H. Kolagani

2010-01-01

485

Pulses inside the pulse mode of operation at RF Gun  

E-print Network

Pulses inside the pulse mode of operation at RF Gun V. Vogel, V. Ayvazyan, K. Floettmann, D. Lipka a PiP mode of operation at RF Gun · What we need, to operate FLASH in the PiP mode · PiP study-Universitaet Bochum) Alternative: SC GUN DC GUN Cold GUN in PiP mode Cold Traveling wave GUN Why we need a PiP mode

486

Prefire identification for pulse power systems  

DOEpatents

Prefires in a high-power, high-frequency, multi-stage pulse generator are detected by a system having an EMI shielded pulse timing transmitter associated with and tailored to each stage of the pulse generator. Each pulse timing transmitter upon detection of a pulse triggers a laser diode to send an optical signal through a high frequency fiber optic cable to a pulse timing receiver which converts the optical signal to an electrical pulse. The electrical pulses from all pulse timing receivers are fed through an OR circuit to start a time interval measuring device and each electrical pulse is used to stop an individual channel in the measuring device thereby recording the firing sequence of the multi-stage pulse generator.

Longmire, Jerry L. (Los Alamos, NM); Thuot, Michael E. (Espanola, NM); Warren, David S. (Los Alamos, NM)

1985-01-01

487

Prefire identification for pulse-power systems  

DOEpatents

Prefires in a high-power, high-frequency, multi-stage pulse generator are detected by a system having an EMI shielded pulse timing transmitter associated with and tailored to each stage of the pulse generator. Each pulse timing transmitter upon detection of a pulse triggers a laser diode to send an optical signal through a high frequency fiber optic cable to a pulse timing receiver which converts the optical signal to an electrical pulse. The electrical pulses from all pulse timing receivers are fed through an OR circuit to start a time interval measuring device and each electrical pulse is used to stop an individual channel in the measuring device thereby recording the firing sequence of the multi-stage pulse generator.

Longmire, J.L.; Thuot, M.E.; Warren, D.S.

1982-08-23

488

Pulse Test of Coil Insulation  

NASA Technical Reports Server (NTRS)

Waveform of back-electromotive force reveals defects. Simple pulse test reveals defects in inductor coils. Devised for use on servovalve solenoid coils on Space Shuttle, test also applicable to transformer windings, chokes, relays, and the like.

Kroy, Ralph E.

1987-01-01

489

Ultrasonic flowmetering with reflected pulses  

E-print Network

A transit time type ultrasonic flowmeter was tested with two different reflected pulse trajectories in flowing air at ambient conditions against an orifice meter. The flowmeter was designed to be highly accurate, to require ...

Hoyle, David C.

1984-01-01

490

Modeling of pulsed propellant reorientation  

NASA Technical Reports Server (NTRS)

Optimization of the propellant reorientation process can provide increased payload capability and extend the service life of spacecraft. The use of pulsed propellant reorientation to optimize the reorientation process is proposed. The ECLIPSE code was validated for modeling the reorientation process and is used to study pulsed reorientation in small-scale and full-scale propellant tanks. A dimensional analysis of the process is performed and the resulting dimensionless groups are used to present and correlate the computational predictions for reorientation performance.

Patag, A. E.; Hochstein, J. I.; Chato, D. J.

1989-01-01

491

Pulse plating of nickel deposits  

SciTech Connect

Pulse plated and conventional nickel deposits have been compared for differences in morphology, mechanical properties, and microstructure. The deposits were obtained from nickel sulfamate, nickel chloride, and Watts nickel plating solutions. No significant differences were found in the direct and pulse current deposits from the sulfamate and chloride solutions; however, significant differences in microstructure, yield strength, and microhardness were observed in deposits from the Watts nickel solution.

Stimetz, C.J.; Stevenson, M.F.

1980-02-01

492

Discrete Pulse Transform of Images  

Microsoft Academic Search

\\u000a The Discrete Pulse Transform (DPT) of images is defined by using a new class of LULU operators on multidimensional arrays.\\u000a This transform generalizes the DPT of sequences and replicates its essential properties, e.g. total variation preservation.\\u000a Furthermore, the discrete pulses in the transform capture the contrast in the original image on the boundary of their supports.\\u000a Since images are perceived

Roumen Anguelov; Inger Fabris-rotelli

2008-01-01

493

Air core pulse transformer design  

Microsoft Academic Search

Cylindrical-air-core pulse transformers capable of passing high-voltage\\/high-energy pulse waveforms with high efficiency and low distortion require a much more delicate design balance of physical dimensions and electrical parameters than iron or ferrite core units. Special computer codes were written to evaluate their performance. The analysis includes calculation of the self and mutual inductances as determined by the dimensions and insulation

J. P. O'Loughlin; J. D. Sidler; Gerry J. Rohwein

1988-01-01

494

Theoretical and Heuristic Synthesis of Digital Spiking Neurons for Spike-Pattern-Division Multiplexing  

NASA Astrophysics Data System (ADS)

A digital spiking neuron is a wired system of shift registers that can generate spike-trains having various spike patterns by adjusting the wiring pattern between the registers. Inspired by the ultra-wideband impulse radio, a novel theoretical synthesis method of the neuron for application to spike-pattern division multiplex communications in an artificial pulse-coupled neural network is presented. Also, a novel heuristic learning algorithm of the neuron for realization of better communication performances is presented. In addition, fundamental comparisons to existing impulse radio sequence design methods are given.

Iguchi, Tetsuro; Hirata, Akira; Torikai, Hiroyuki

495

Synthesis of droop compensated pulse forming networks for generating flat top, high energy pulses into variable loads from pulsed transformers  

Microsoft Academic Search

It is shown that a flat-top, constant-power, long-output pulse can be obtained from a droop-compensated OFN (pulse forming network)-driven pulsed transformer. It is shown that such transformers are highly efficient, and seem particularly feasible for high-voltage, long-pulse applications. Examples are given for generating 100 GW, high-energy pulses (250-1000 kJ) into variable resistive loads from a 20 kV PFN

P. M. Ranon; D. J. Hall; J. P. O'Loughlin; R. L. Schlicher; W. L. Baker; D. Dietz; M. C. Scott

1988-01-01

496

Femtosecond pulse imaging: ultrafast optical oscilloscope  

E-print Network

waves of a shaped femtosecond pulse are mixed with those of a transform-limited pulse to generateFemtosecond pulse imaging: ultrafast optical oscilloscope P. C. Sun, Y. T. Mazurenko,* and Y 12, 1996 A nonlinear optical processor that is capable of real-time conversion of a femtosecond pulse

Fainman, Yeshaiahu

497

A programmable Fresnel transform pulse shaper  

E-print Network

A programmable Fresnel transform pulse shaper G. M´inguez-Vega1, J.D. McKinney2 and A.M. Weiner2 1@purdue.edu Abstract: We demonstrate the first reprogrammable Fresnel transform pulse shaper based on a modified direct space-to-time pulse shaping appa- ratus. In our approach, the pulse shaping lens and mask

Purdue University

498

Helical Pulse Line Structures for Ion Acceleration  

SciTech Connect

The basic concept of the ''Pulse Line Ion Accelerator'' is presented, where pulse power sources create a ramped traveling wave voltage pulse on a helical pulse line. Ions can surf on this traveling wave and achieve energy gains much larger than the peak applied voltage. Tapered and untapered lines are compared, and a transformer coupling technique for launching the wave is described.

Briggs, R.J.; Reginato, L.L.; Waldron, W.L.

2005-05-01

499

Compression of amplified chirped optical pulses  

Microsoft Academic Search

A system is reported which transposes a short-pulse amplification technique employed in radar to the optical regime and that, in principle, should be capable of producing short (1 pc or less) pulses with energies at the Joule level. The technique involves stretching a chirped optical pulse and then amplifying it before recompression. To date, 2-ps pulses with an energy of

D. Strickland; G. Mourou

1985-01-01

500

Geolocation of Multiple Pulses in Lightning Pulse Trains  

NASA Astrophysics Data System (ADS)

During 2013, Vaisala has been upgrading all sensors in the U.S. National Lightning Detection Network™ (NLDN) to the new LS7002 sensor (see Nag et al., this conference for further details). One of the capabilities of this improved sensor is the ability to process multiple pulses in cloud discharge pulse trains, or 'bursts', and send the information back to the central processor. To accompany the new sensor development, we have also deployed a new localization algorithm that properly handles inter-pulse time intervals within such pulse bursts and is capable of determining the positions of multiple pulses within bursts. These improvements are expected to improve the cloud flash detection efficiency of the NLDN as well as the spatial resolution of cloud flashes. During the summer of 2013, data from some small thunderstorms were processed using the original localization algorithm and again using the burst-processing algorithm. The present analysis compares both sets of results to high-resolution VHF lightning mapping data from a Lightning Mapping Array to assess the extent to which those anticipated improvements have been realized, to identify where in the flash lifecycle these bursts most readily occur, and to determine where there may be room for additional improvements.

Murphy, M. J.; Nag, A.; Cramer, J.; Pifer, A.

2013-12-01