Results 151 to 160 of about 567,106 (189)

A compact ultra wide impedance bandwidth antenna

IEEE Antennas and Propagation Society Symposium, 2004., 2004
This paper describes an electric dipole and a magnetic dipole (slot antenna) which are connected in parallel to achieve an ultra wide impedance bandwidth antenna. This makes it suitable for application to ultra wideband communications systems and to communication systems that cover a number of distinct and wide spread frequency bands.
R.H. Johnston, T.C. Choi, E. Tung
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Artificial Impedance Surface for widening the bandwidth of an antenna

Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation, 2012
In this communication, Artificial Impedance Surfaces (AIS) based on patches from High Impedance Surface (HIS) are considered. The possibility to use the patch width as an additional degree of freedom for antennas design is investigated. Within the limitation of a single linear polarization, rectangular patches of this AIS allow adjusting the surface ...
Julien Sarrazin, Anne-Claire Lepage, Xavier Begaud   +2 more
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Bandwidth Enhancement of Dual Band Impedance Transformer with Transmission Zero

2018 9th International Conference on Computing, Communication and Networking Technologies (ICCCNT), 2018
A dual band planar impedance matching network using a compact quarter wave transformer with wideband characteristics is presented. The quarter wave section can be realized as a cascade of $\boldsymbol{T}$ networks. The degree of compactness and bandwidth enhancement depends upon the number of stages used to implement the quarter wave section.
Kochar Inderkumar, Pallav Rathore, Kaustubh Prabhu   +2 more
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Impedance, axial-ratio, and receive-power bandwidths of microstrip antennas

IEEE Antennas and Propagation Society International Symposium (IEEE Cat. No.02CH37313), 2003
Closed-form expressions for the impedance and axial-ratio bandwidths of a single-feed circularly polarized microstrip antenna have been derived. Receive-power bandwidths for both linearly and circularly polarized microstrip antennas have also been derived, which quantify the bandwidths when the microstrip antennas are used as receivers.
W.L. Langston, D.R. Jackson
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Drum roll: increasing bandwidth through passive impedance modulation

Proceedings of International Conference on Robotics and Automation, 2002
People can accomplish many high bandwidth tasks despite the slow response of the neuromuscular system. Reaction times are well over 100 ms, but skilled drummers can play a drum roll at over 30 Hz. Drummers take advantage of a passive dynamic interaction: they let the drumstick bounce against the drum head at least twice on each hand stroke. Because the
Aram Z. Hajian, Daniel S. Sanchez, Robert D. Howe   +2 more
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Ultra‐wideband microstrip antenna with enhanced impedance bandwidth

Microwave and Optical Technology Letters, 2010
AbstractThis article presents a novel ultra‐wideband (UWB) microstrip‐fed planar monopole antenna composed of a rectangular patch and a ground‐plane π‐shape slot structure. Impedance bandwidth of the proposed antenna is ∼147% over an UWB frequency range between 3 and 19.7 GHz satisfying FCC's requirements for an antenna by a factor in excess of twofold.
Mohammad Naser‐Moghadasi, R.A. Sadeghzadeh, Morteza Katouli, Bal S. Virdee   +3 more
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Cryogenic amplifier for intermediate source impedance with gigahertz bandwidth

Applied Physics Letters, 2006
We demonstrate a cryogenic amplifier for intermediate impedance sources, which operates from dc up to 1GHz. The amplifier is based on rf operation of many parallelly coupled single-electron transistors (SETs). Unlike the ordinary radio-frequency single-electron transistor this amplifier operates without a tank circuit, impedance matching is achieved by
S. Gustavsson, D. Gunnarsson, P. Delsing
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Bandwidth Enhancement of Traveling-Wave Photodetector by Impedance Mismatch

Japanese Journal of Applied Physics, 2003
In this paper, we report bandwidth enhancement phenomena of traveling-wave photodetectors (TWPDs) by output impedance mismatch with an open input facet. The impulse response obtained by the extended finite difference time domain (FDTD) method shows that internal reflection of microwaves with a negative reflection coefficient at the load enlarges the ...
Soon Cheol Kong, Young Wan Choi
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Lossless impedance matching optimization for increasing bandwidth of antennas

2015 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 2015
In the design of RF radiators, impedance matching has been costing a significant amount of time and energy. Approaches to solve impedance matching problems mainly rely on computer-aided numerical optimizations, nowadays. An approach based on the MATLAB Global Optimization Toolbox™ is proposed in this paper. This approach combines brute-force techniques
Kaiming Li, James K. Breakall
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Effects of glottal termination impedance on formant frequencies and bandwidths

The Journal of the Acoustical Society of America, 1983
The finding that synthetic speech, based on the customary linear model of acoustic speech production, often sounds somewhat machinelike, has motivated various attempts to refine the model. Our approach to the problem concentrates on variations in formant parameters due to the changing termination impedance at the glottis.
L. Boves, B. Cranen
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