The Experts below are selected from a list of 17157 Experts worldwide ranked by ideXlab platform
Wen-thong Chang - One of the best experts on this subject based on the ideXlab platform.
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M-ary wavelet transform and formulation for perfect reconstruction in M-band filter bank
IEEE Transactions on Signal Processing, 1994Co-Authors: Ming-haw Yaou, Wen-thong ChangAbstract:The binary wavelet transform is generalized and extended to the M-ary biorthonormal case. The computational equivalence between the discrete wavelet analysis and the M-band multirate signal filtering is indicated. The equivalence allows the perfect reconstruction requirement in a filter bank to be investigated from the vector space decomposition/reconstruction in wavelet analysis. From the construction of the biorthonormal wavelet bases, the necessary and sufficient condition for the filters in a perfect reconstruction filter bank is formulated. Under this formulation, an additional optimization procedure is then used to model the frequency domain requirement in filter bank design.
Frank Kurth - One of the best experts on this subject based on the ideXlab platform.
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Filter bank tree and M-band wavelet packet algorithms in audio signal processing
IEEE Transactions on Signal Processing, 1999Co-Authors: Frank KurthAbstract:This article investigates M-band wavelet packets and a generalized\nframework for the design and efficient utilization of multirate filter\nbank trees (FBTs). While the increased flexibility of M-band wavelet\nover the standard two-band wavelet packets is desirable in many signal\nprocessing applications, the possibilities in time-frequency design\nusing arbitrary filter bank cascades are even greater. We show how to\nconstruct FBTs for arbitrary given tree-like splits of the\ntime-frequency plane. Furthermore, we give an explicit construction for\nefficient simultaneous subband and spectral analysis in the general FRT\ncase. Results from audio signal processing applications show that the\nproposed methods in many cases yield better results than those using\nstandard wavelet packets
R Kandpal - One of the best experts on this subject based on the ideXlab platform.
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the kink band triangle a triangular plot for paleostress analysis from kink bands
Journal of Structural Geology, 1998Co-Authors: Deepak Srivastava, Richard J Lisle, M. Imran, R KandpalAbstract:A kink-band can be graphically represented as a point on an equilateral triangle whose vertices define the angles between external foliation and kink plane, between internal foliation and kink plane, and between internal- and external-foliations. Four typical deformation paths that correspond to the four modes of kink-band growth can be discerned on this triangle. The three linear relationships between each of the kink-band angles and the inclination of the σ1-axis with respect to the unrotated layering can be transformed into a straight line on the triangular plot. Application of this plot in paleostress analysis is demonstrated by several examples. The method, however, yields best results when a large number of data on the kink-band angles are plotted and contoured on the triangular graph.
Gabriel M. Rebeiz - One of the best experts on this subject based on the ideXlab platform.
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Optimization of distributed MEMS transmission-line phase shifters-U-band and W-Band designs
IEEE Transactions on Microwave Theory and Techniques, 2000Co-Authors: N. Scott Barker, Gabriel M. RebeizAbstract:The design and optimization of distributed micromechanical system (MEMS) transmission-line phase shifters at both U- and W-Band is presented in this paper. The phase shifters are fabricated on 500 μm quartz with a center conductor thickness of 8000 Å of gold. The U-band design results in 70°/dB at 40 GHz and 90°/dB at 60 GHz with a 17% change in the MEMS bridge capacitance. The W-Band design results in 70°/dB from 75 to 110 GHz with a 15% change in the MEMS bridge capacitance. The W-Band phase-shifter performance is limited by the series resistance of the MEMS bridge, which is estimated to be 0.15 Ω. Calculations demonstrate that the performance of the distributed MEMS phase shifter can be greatly increased if the change in the MEMS bridge capacitance can be increased to 30% or 50%. To our knowledge, these results present the best published performance at 60 and 75-110 GHz of any nonwaveguide-based phase shifter.
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Micromachined W-Band filters
IEEE Transactions on Microwave Theory and Techniques, 1996Co-Authors: S.v. Robertson, Linda P. B. Katehi, Gabriel M. RebeizAbstract:Results are presented for high performance planar W-Band filters based on silicon micromachining techniques common in microsensor fabrication. Two types of micromachined planar transmission lines are studied: microshield line and shielded membrane microstrip (SMM) line. In both of these structures, the conducting lines are suspended on thin dielectric membranes. These transmission lines are essentially "floating" in air, possess negligible levels of dielectric loss, and do not suffer from the parasitic effects of radiation and dispersion. A 90 GHz low pass filter and several 95 GHz bandpass filters are tested and display excellent performance which cannot be achieved with traditional substrate supported circuits in CPW or microstrip configurations. A full-wave finite-difference time-domain (FDTD) technique verifies the measured performance of the W-Band circuits and provides a basis for comparison between the performances of membrane supported circuits and equivalent substrate supported circuits.
Hongfu Meng - One of the best experts on this subject based on the ideXlab platform.
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Design of W-Band Microstrip Antenna Array
2019 IEEE Asia-Pacific Microwave Conference (APMC), 2019Co-Authors: Hongfu MengAbstract:A $8\times 8$ microstrip antenna array for W-Band application is presented in this paper. The radiation element of the antenna array is rectangular microstrip patch fed from the non-radiating edge. A 1 to 64 microstrip line power divider is proposed to feed the $8 \times 8$ radiation patches. The radiation elements and the microstrip line feed network are on the same layer, so the antenna PCB only has two layers. By optimizing design the radiation patches and feed network, the antenna array shows good performance at W-Band with the center frequency 94GHz. The microstrip antenna array and a WR10 waveguide to microstrip transition structure are fabricated and measured. The measured results show that the antenna array has a −10dB bandwidth of 7% and a peak gain of 21.4dBi at 94 GHz.
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Design of W-Band Microstrip Antenna Array
2019 IEEE Asia-Pacific Microwave Conference (APMC), 2019Co-Authors: Hongfu MengAbstract:A 8×8 microstrip antenna array for W-Band application is presented in this paper. The radiation element of the antenna array is rectangular microstrip patch fed from the non-radiating edge. A 1 to 64 microstrip line power divider is proposed to feed the 8 ×8 radiation patches. The radiation elements and the microstrip line feed network are on the same layer, so the antenna PCB only has two layers. By optimizing design the radiation patches and feed network, the antenna array shows good performance at W-Band with the center frequency 94GHz. The microstrip antenna array and a WR10 waveguide to microstrip transition structure are fabricated and measured. The measured results show that the antenna array has a -10dB bandwidth of 7% and a peak gain of 21.4dBi at 94 GHz.
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W-Band microstrip reflectarray with single-layer
2015 Asia-Pacific Microwave Conference (APMC), 2015Co-Authors: Bing Li, Hongfu MengAbstract:This paper describes a W-Band microstrip reflectarray antenna with a single-layer substrate. The reflector element is a double resonant ring-round mixed structure, in which the circle radius and ring inner radius are changed. The combination of the two types elements can achieve a full 360° range of phase shifts. Using this technique, a 50 by 50 W-Band reflectarray antenna has been designed. The feasibility of this design is verified with simulated and measured results.
