The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
Tian-bo Deng - One of the best experts on this subject based on the ideXlab platform.
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Complex-Coefficient variable filter design using successive vector-array-decomposition
2005 IEEE International Symposium on Circuits and Systems, 2005Co-Authors: Tian-bo DengAbstract:Singular-value-decomposition (SVD) can be efficiently utilized to obtain the optimal vector-array-decomposition (VAD) for simplifying Real-Coefficient variable digital filter design problem, but the SVD-based VAD methods cannot be utilized to design complex-Coefficient variable filters. The paper proposes a successive algorithm for decomposing an arbitrary multi-dimensional complex array into the VAD form, and thus a complex-Coefficient digital filter with an arbitrary variable frequency response can be easily obtained through complex-Coefficient constant filter design and multi-dimensional polynomial fitting. The new VAD algorithm successively decomposes the complex array and its residual arrays into the vector-array pairs stage-by-stage, and each stage contains an iterative optimization that can be easily solved in a closed-form. Our computer simulations have verified that the successive VAD converges very fast to the optimal solution.
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Design of complex-Coefficient variable digital filters using successive vector-array decomposition
IEEE Transactions on Circuits and Systems I: Regular Papers, 2005Co-Authors: Tian-bo DengAbstract:Singular-value decomposition (SVD) can be efficiently utilized to obtain the optimal vector-array decomposition (VAD) for simplifying Real-Coefficient variable digital filter design problem, but the SVD-based VAD methods are not applicable to the design of complex-Coefficient variable filters. This paper proposes a successive algorithm for decomposing arbitrary multidimensional complex array into the VAD form, and thus, a complex-Coefficient variable digital filter with arbitrary variable frequency response can be easily obtained through constant complex-Coefficient filter design and multidimensional polynomial fitting. The new VAD algorithm successively decomposes the complex array and its residual arrays into the vector-array pairs stage by stage, and each stage contains an iterative optimization that can be easily solved in a closed-form. Our computer simulations have demonstrated that the successive VAD converges very fast to the optimal solution.
A.t. Farn - One of the best experts on this subject based on the ideXlab platform.
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On the sensitivity of Realizations of Real Coefficient digital filters using complex arithmetic
Proceedings of ICASSP '94. IEEE International Conference on Acoustics Speech and Signal Processing, 1994Co-Authors: C. Tsai, A.t. FarnAbstract:Previously, new structures using complex arithmetic were proposed for the implementation of Real Coefficient IIR digital filters. The quantization of the Real-equivalent of a complex Coefficient in these filters violates an assumption usually adopted in the analysis of Coefficient sensitivity, i.e., quantization errors are uncorrelated to each other. In the present paper, a simple expression is derived to measure the L/sub 2/ sensitivity, of structures using complex arithmetic. Then, an explicit expression of the L/sub 2/ sensitivity is obtained for second-order digital filters with minimum norm.
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ICASSP (3) - On the sensitivity of Realizations of Real Coefficient digital filters using complex arithmetic
Proceedings of ICASSP '94. IEEE International Conference on Acoustics Speech and Signal Processing, 1994Co-Authors: C. Tsai, A.t. FarnAbstract:Previously, new structures using complex arithmetic were proposed for the implementation of Real Coefficient IIR digital filters. The quantization of the Real-equivalent of a complex Coefficient in these filters violates an assumption usually adopted in the analysis of Coefficient sensitivity, i.e., quantization errors are uncorrelated to each other. In the present paper, a simple expression is derived to measure the L/sub 2/ sensitivity, of structures using complex arithmetic. Then, an explicit expression of the L/sub 2/ sensitivity is obtained for second-order digital filters with minimum norm. >
T.q. Nguyen - One of the best experts on this subject based on the ideXlab platform.
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Theory and lattice structure of complex paraunitary filterbanks with filters of (Hermitian-)symmetry/antisymmetry properties
IEEE Transactions on Signal Processing, 2001Co-Authors: T.q. Nguyen, G. StrangAbstract:The theory of the Real-Coefficient linear-phase filterbank (LPFB) is extended to the complex case in two ways, leading to two generalized classes of M-channel filterbanks. One is the symmetric/antisymmetric filterbank (SAFB), where all filters are symmetric or antisymmetric. The other is the complex linear phase filterbank (CLPFB), where all filters are Hermitian symmetric or Hermitian antisymmetric and, hence, have the linear-phase property. Necessary conditions on the filter symmetry polarity and lengths for the existence of permissible solutions are investigated. Complete and minimal lattice structures are developed for the paraunitary SAFB and paraunitary CLPFB, where the channel number M is arbitrary (even or odd), and the subband filters could have different lengths. With the elementary unitary matrices in the structure of the paraunitary SAFB constrained to be Real and orthogonal, the structure covers the most general Real-Coefficient paraunitary LPFBs. Compared with the existing results, the number of parameters is reduced significantly.
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The design of arbitrary FIR digital filters using the eigenfilter method
IEEE Transactions on Signal Processing, 1993Co-Authors: T.q. NguyenAbstract:The design of finite impulse response (FIR) digital filters for approximating an arbitrary function (in both magnitude and phase) in the least-square sense is studied. The design method is based on the computation of an eigenvector of an appropriate Real, symmetric and positive-definite matrix. The design of the complex-Coefficient filter is shown to be an extension of the design of the Real-Coefficient filter. Several design examples, including the constant-group-delay filters and digital phase all-pass filters, are presented. Comparisons to existing methods are made.
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The eigenfilter for the design of linear-phase filters with arbitrary magnitude response
[Proceedings] ICASSP 91: 1991 International Conference on Acoustics Speech and Signal Processing, 1991Co-Authors: T.q. NguyenAbstract:The author studies the design of linear-phase FIR (finite impulse response) digital filters to approximate linear-phase functions with arbitrary magnitude response. The design method is based on the computation of an eigenvector of an appropriate Real, symmetric, and positive-definite matrix. The design of complex-Coefficient linear-phase filters is shown to be an extension of the design of the Real-Coefficient filter. Several examples are presented which demonstrate the usefulness of the approach.
Len T. Bruton - One of the best experts on this subject based on the ideXlab platform.
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Beamforming of Broad-Band Bandpass Plane Waves Using Polyphase 2-D FIR Trapezoidal Filters
IEEE Transactions on Circuits and Systems I: Regular Papers, 2008Co-Authors: Thushara K. Gunaratne, Len T. BrutonAbstract:A new discrete-domain method is proposed for the beamforming of temporally broad-band bandpass plane waves (PWs) using a Real-Coefficient 2-D spatio-temporal (ST) finite-impulse response (FIR) filter having a novel rectangularly symmetric double-trapezoidal-shaped passband. The arriving temporally broad-band-bandpass ST PWs are received by a 1-D uniformly distributed sensor array. The sensor signals are pre-filtered, down-shifted to the intermediate frequency (IF) band, low-pass filtered and synchronously sampled by the Real IF tri-stage temporal sampler array, resulting in a Real-valued 2-D sampled sequence. The beamforming operation is then carried out on this 2-D sampled sequence using the Real-Coefficient 2-D FIR double-trapezoidal filter. Arithmetic complexity in the hardware implementation of the 2-D FIR double-trapezoidal filter is significantly reduced by using an array of Real-Coefficient polyphase 1-D FIR filters. Experimental results have confirmed that this method is capable of enhancing the desired temporally broad-band-bandpass ST PWs according to their directions of arrival under severe co-channel interference.
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Beamforming of Temporally-Broadband-Bandpass Plane Waves using Real Polyphase 2-D FIR Trapezoidal Filters
2007 IEEE International Symposium on Circuits and Systems, 2007Co-Authors: Thushara K. Gunaratne, Len T. BrutonAbstract:A new discrete-domain method is proposed for the beamforming of two-dimensional (2D) temporally-broadband-bandpass (BB-BP) plane waves (PWs) using 2D spatiotemporal (ST) FIR filter having a novel rectangularly-symmetric double-trapezoidal-shaped passband. A Real-Coefficient polyphase 2D FIR filter structure is used to reduce the arithmetic complexity of the hardware implementation. Measured spatiotemporal performance has confirmed that this method is capable of selectively enhancing 2D temporally broadband-bandpass (BB-BP) ST PWs according to their directions of arrival (DOAs) under severe co-channel interference.
SUNG TEK KAHNG - One of the best experts on this subject based on the ideXlab platform.
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An Improved Distributed Equivalent Circuit Modeling for RF Components by Real-Coefficient AFS Technique
Journal of Electrical Engineering & Technology, 2011Co-Authors: Jae-hyeong Ko, Hyun Paek, SUNG TEK KAHNGAbstract:In this paper, a Real-Coefficient approach to Adaptive Frequency Sampling (AFS) technique is developed for efficient equivalent circuit modeling of RF components. This proposed method is advantageous than the vector fitting technique and the conventional AFS method in terms of fewer samples leading to a lower order of a rational function on a given data and to a direct conversion to an equivalent circuit for PSPICE(Personal Simulation Program with Integrated Circuit Emphsis) simulation, respectively. To validate the proposed method, the distributed equivalent circuit of a presented multi-layered RF low-pass filter is obtained using the proposed Real-Coefficient AFS, and then comparisons with EM simulation and circuit simulation for the device under consideration are achieved.
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Equivalent circuit model order reduction by Real-Coefficient AFS
2011 IEEE International Symposium on Electromagnetic Compatibility, 2011Co-Authors: SUNG TEK KAHNG, Raj MittraAbstract:In this paper, the Adaptive Frequency Sampling(AFS) technique for Model Order Reduction is modified to macromodel the RF components. The conventional AFS can just express the frequency response as a rational function, but ends up with inefficiency in macromodelling So the proposed scheme here enables the AFS to macromodel the problem by finding the equivalent circuit of the frequency response, since the Coefficients of the rational function are made Real-valued and easily arranged to the well-known configurations of resistors, capacitors and inductors. The validity of the proposed technique is watched by showing the accuracy of the equivalent circuit compared to the original data and vector fit curve of an RF DGS filter as an instance&x2025;
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Improved equivalent circuit modeling for RF components by the Real-Coefficient adaptive frequency sampling technique
Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation, 2010Co-Authors: Hyun Paek, SUNG TEK KAHNGAbstract:In this paper, the Real-Coefficient version of Adaptive Frequency Sampling(AFS) technique is developed for efficient equivalent circuit modeling of RF components. This proposed method is advantageous over the vector fitting technique and the conventional AFS method in terms of fewer samples leading to a lower order of a rational function on a given data and direct conversion to an equivalent circuit for the PSPICE simulation, respectively. To validate the proposed method, the 3D field analysis data of a multilayered PCB is reduced to the equivalent circuit by the Real-Coefficient AFS and two data will be shown to agree.
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Real-Coefficient AFS derived for the equivalent circuit modelling of RF passives
2010 Asia-Pacific International Symposium on Electromagnetic Compatibility, 2010Co-Authors: SUNG TEK KAHNG, Jeongho JuAbstract:In this paper, the Adaptive Frequency Sampling(AFS) technique is modified to macromodel the RF components. The conventional AFS can just express the frequency response as a rational function, but ends up with inefficiency in macromodelling So the proposed scheme here enables the AFS to macromodel the problem by finding the equivalent circuit of the frequency response, since the Coefficients of the rational function are made Real-valued and easily arranged to the well-known configurations of resistors, capacitors and inductors. The validity of the proposed technique is watched by showing the accuracy of the equivalent circuit compared to the original data and vector fit curve of an RF DGS filter as an instance..
