Results 241 to 250 of about 88,039 (271)

Broadband electrical impedance matching for piezoelectric ultrasound transducers

IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2011
This paper presents a systematic method for designing broadband electrical impedance matching networks for piezoelectric ultrasound transducers. The design process involves three steps: 1) determine the equivalent circuit of the unmatched piezoelectric transducer based on its measured admittance; 2) design a set of impedance matching networks using a ...
Haiying, Huang, Daniel, Paramo
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Electrical Impedance Matching Between Piezoelectric Transducer and Power Amplifier

IEEE Sensors Journal, 2020
Electrical impedance matching network (EIMN) is important for the piezoelectric transducer to transmit high-power acoustic signal over a wide bandwidth. Different from the impedance matching between transducers and interface devices with a fixed impedance of $50\Omega $ , this paper presents a novel method of designing an EIMN between transducer ...
Hanyun Zhou, S. H. Huang, Wei Li
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Non-Foster impedance matching of electrically small antennas

2010 IEEE Antennas and Propagation Society International Symposium, 2010
When the size of an antenna is electrically small, the antenna is neither efficient nor a good radiator because most of the input power is stored in the reactive near-field region and little power is radiated in the far-field region. As demonstrated in [1]- [2], the radiation quality factor of small antennas is definitely high.
null Keum-Su Song, R G Rojas
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Non-Foster Impedance Matching of Electrically-Small Antennas

IEEE Transactions on Antennas and Propagation, 2009
Electrically-small antennas present high-Q impedances characterized by large reactances and small radiation resistances. For such antennas, the effectiveness of passive matching is severely limited by gain-bandwidth theory, which predicts narrow bandwidths and/or poor gain.
S.E. Sussman-Fort, R.M. Rudish
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An electrically small impedance-matched microstrip antenna design

IEEE Antennas and Propagation Society International Symposium (IEEE Cat. No.02CH37313), 2003
In traditional antenna design, a rule of thumb is that an impedance-matched antenna has to be wavelength compatible in size. It is not possible to design an electrically small antenna with matched impedance. In our previous studies, it was found that the operating frequency of a patch antenna could be reduced to 1/3 or even 1/4 of the original ...
M.C. Liang, Y.M. Chen, C.C. Huang, W.S. Chen   +3 more
openaire   +1 more source

A design methodology for impedance-matched Electrically Small parasitic superdirective arrays

2015 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 2015
This paper presents a method for designing impedance-matched parasitic superdirective Electrically Small Antenna (ESA) arrays. The proposed method uses the current excitation coefficients for calculating the required loads for the parasitic elements. The proposed method is validated via the design of a parasitic two-element superdirective ESA.
Haskou, Abdullah, Collardey, Sylvain, Sharaiha, Ala   +2 more
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Wideband, Non-Foster Impedance Matching of Electrically Small Transmitting Antennas

IEEE Transactions on Antennas and Propagation, 2018
Electrically small antennas (ESAs) can be passively matched only over very narrow bandwidths and the resulting antennas have low gains. These are the major limiting factors for ESAs used in transmit applications, especially at high-frequency (HF) and lower Very HF frequency bands.
Ting-Yen Shih, Nader Behdad
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Electrical impedance matching based on piezoelectric ceramics for energy harvesting application

Materials Technology, 2020
Piezoelectric energy harvesting is one of the promising energy sources for wireless sensor networks and integrated devices.
Qingping Wang, Sha Li, Jin An Sam Oh, Tian Wu   +3 more
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Wireless Excitation and Electrical Impedance Matching of Piezoelectric Wafer Active Sensors

Volume 2: Mechanics and Behavior of Active Materials; Integrated System Design and Implementation; Bio-Inspired Materials and Systems; Energy Harvesting, 2012
Wireless ultrasound inspections using Piezoelectric Wafer Active Sensors (PWAS) are attractive for Structural Health Monitoring (SHM). However, the impedance mismatch between the PWAS and the wireless transponder reduces the wirelessly transmitted signal strength.
Rashed Hossain Bhuiyan, MD Mazharul Islam, Haiying Huang   +2 more
openaire   +1 more source

Electrical Impedance Matching of PVDF Ultrasonic Transducers

2004
One of the objectives of this work is to improve PVDF ultrasonic transducers characteristics by electrical means. It is feasible to enhance the frequency bandshape and the overall power transfer efficiency in high-Q acousto-electric resonators by balancing the source impedance with the transducer electrical impedance using some form of lumped component
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