Title :
Impedance matrix compression using an effective quadrature filter
Author :
Huang, J.-M. ; Leou, J.-L. ; Jeng, S.-K. ; Tarng, J.H.
Author_Institution :
Dept. of Commun. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
fDate :
8/1/2000 12:00:00 AM
Abstract :
An effective quadrature mirror filter (QMF) proposed by Vaidyanathan and Huong (1988) has been used to solve 2D scattering problems. QMF has been popular for some time in digital signal processing, under the names of multirate sampling, wavelets, etc. In this work, the impulse response coefficients of QMF were used to construct the wavelet transform matrix. Using the matrix to transform the impedance matrices of 2D scatterers produces highly sparse moment matrices that can be solved efficiently. Such a presentation provides better sparsity than the celebrated and widely used Daubechies wavelets. These QMF coefficients are dependent on the filter parameters such as transition bandwidth and filter length. It was found that the sharper the transition bandwidth, the greater the reduction in nonzero elements of the impedance matrix. It also can be applied in the wavelet packet algorithm to further sparsify the impedance matrix. Numerical examples are given to demonstrate the effectiveness and validity of our finding
Keywords :
channel bank filters; electromagnetic wave scattering; impedance matrix; lattice filters; quadrature mirror filters; sparse matrices; transient response; wavelet transforms; 2D scattering problems; QMF coefficients; effective quadrature filter; filter length; filter parameters; impedance matrix compression; impulse response coefficients; nonzero elements; quadrature mirror filter; sparse moment matrices; sparsity; transition bandwidth; wavelet packet algorithm; wavelet transform matrix;
Journal_Title :
Microwaves, Antennas and Propagation, IEE Proceedings
DOI :
10.1049/ip-map:20000361
