Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 44 for “"return loss"”.
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Design of a High Temperature GaN-Based Variable Gain Amplifier for Downhole Communications
… -11.57 dBm at 230 °C (-3.63 dBm at 25 °C). Input return loss is below 19 dB, and output return loss is below 12 dB across the entire gain control range from 25 °C to 230 °C. The variation with temperature (25 °C to 230 °C) is 1 dB for maximum gain, and 4.7 dB for gain control range. The total …
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Design multilayer bandpass filter using hairpin resonator for digital broadcasting
… line band pass filter ,the passband insertion loss using FR4 Material is -5.651dB and when using RO3003 Material is -1.79dB .The passband return loss is -30.614dB for the FR4 material type and -18.52 dB for RO3003 material type. For multi layer band pass filter the passband insertion loss using …
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Human identification through wearable antenna characteristics
… demonstrate the new biometric concept using return loss characteristics to identify individuals on multiple body parts. An optimized directional coupler design is implemented with the antenna to optimize the characteristic feature detection range for human identification. Experiments …
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An investigation of nanoscale materials and their incorporation in patch antenna for high frequency applications
… has complex permittivity of 1.36±5% and a loss tangent of 2.4E-04±4.8E-04 which was measured using Spilt-Post Dielectric Resonators (SPDR) technique at National Physics Laboratory, Teddington, London. A diamond-shaped MPAs on RT Duriod material were simulated and fabricated using …
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Gap Waveguide Array Element Filters
… with a bandwidth of 4 GHz and 20 dB of passband return loss that was used to develop several filter components for the other filter designs. The filter was integrated with a slotted waveguide antenna array and the effects of the coupling between adjacent filter channels was investigated. The …
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Variable permittivity dielectric material loaded stepped-horn antenna
… terminated by an infinite metallic flange. Input return loss, gain, aperture efficiency and cross-polarization characteristics are studied. Comparisons indicate that any kind of loading with dielectric material along the taper tend to improve the gain level for the entire bandwidth, aperture …
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Design and implementation of L and X-band filters for the NeXtRAD front end
… at 2.86 times the operating frequency. The return loss of the filter was 19.52 dB, and the insertion loss at mid-band was 0.14 dB. The measured filter agreed extremely well with the L-band specifications. The X-band iris coupled filter was also designed, manufactured and measured. The narrow …
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Gallium Nitride-Based HEMTs for Microwave Power and Noise: Physics and Application
… a noise figure of 3.5 dB, gain of 7.5 dB, input return loss of -7.5 dB, and output return loss of -15 dB at 8.5 GHz. The MMIC was fabricated on layers grown by MOCVD on a silicon carbide substrate and employed a 0.25-mum x 150-mum AlGaN/GaN HEMT. These results demonstrate the potential for the …
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Implementation and evaluation of echo cancellation algorithms
… on their convergence rate, steady state echo return loss (ERL), and complexity of implementation. While LMS is simple, its convergence rate is dependent on the eigenvalue spread of the signal. In particular, it converges slowly with speech as input. This problem is mitigated in NLMS. The …
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Size reduction of vivaldi antenna array for microwave imaging
… to obtain a compact antenna with an acceptable return loss and radiation pattern. Hence, a single element antenna of size (36×42.8
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Non-foster matching of an RFID antenna
… is recommended to tune antennas to lower the return loss at operating frequency, in order to achieve an optimized range for use with passive tags.
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A nonlinear statistical MESFET model using low order statistics of equivalent circuit model parameter sets
… and accurately predicts output power, input return loss, and power added efficiency. Not only is nominal performance good, but the spreads of amplifier performance seen over many wafers and several lots is represented well. The model consists of capturing low order statistics (means, …
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Development of triple band planar inverted F-antenna (PIFA) for GSM 800 MHz, DCS 1800 MHz and Bluetooth 2400 MHz
… bands are 0.966 GHz, 1.836 GHz and 2.50 GHz with return loss of -25.84 dB, -32.52 dB and -24.2 dB respectively. Comparison for the measurement and the simulation are carried out in terms of S11 parameter, bandwidth, VSWR, input impedance and radiation pattern.
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Design of fractal minkowski diversity antenna for LTE and WIFI application
… properties were observed from the measurement of return loss, standing wave ratio (SWR), bandwidth and radiation pattern.
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Development of triple band planar inverted-H antenna for DCS, WIMAX and WLAN application
… bands are 1.764 GHz, 2.739 GHz and 3.17 GHz with return loss of -15.14 dB, -15.88 dB and -25.77 dB respectively. Comparison for the measurement and the simulation are carried out in terms of S11 parameter, bandwidth, VSWR, input impedance and radiation pattern.
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Novel narrowband microstrip filters for wireless communications systems
… (shaip-cutoff frequency response, low insertion-loss, high return-loss, and high out-of-band isolation), compact size, low cost, and ease of integration in subsystem and systems. The analysis and modelling methods for these resonators includes a transmission-line theory, ABCD matrix, and EM …
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Novel metamaterial frequency discriminating devices for next generation wireless communication systems
… frequency response, low passband insertion-loss and high return-Joss, high out-af-band rejection, compact size, low cost and ease of integration. The filters are approximately 70% smaller than their conventional counterparts. Analysis and mathematical modeling of these microstrip devices …
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Fabrication of Superconducting Reflectionless Filters for Quantum Microwave Circuits
… Cryogenic measurements at 20 mK demonstrate high return loss, confirming the viability of these filters for co-fabrication with traveling-wave parametric amplifiers (TWPAs) and circuit quantum electrodynamics (cQED) architectures. The filters exhibit low insertion loss in the passband to maintain …
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Exploration of alternative algorithms for multi-channel acoustic echo cancellation
… such as the Word Error Rate (WER) and Echo Return Loss Enhancement (ERLE) help to distinguish performance among the two adaptive filter algorithms. For the single channel case, simulations confirm the cancellation and convergence rate advantage of the Kalman filter, in full-band, but the …
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Design and implementation of the pillbox antenna for SASARII
… tests which include power gain, 3 dB beamwidth, return loss and cross-polarization measurements are discussed. The test results are analyzed and compared to the simulations and theoretical predictions to measure the performance of the antenna. This dissertation winds up by discussing the …
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