Browsing by Author "PENG, ST"

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FULL-WAVE ANALYSIS OF LOSSY QUASI-PLANAR TRANSMISSION-LINE INCORPORATING THE METAL MODES
(1990-12-01)
TZUANG, CKC
;
CHEN, CD
;
PENG, ST
;
傳播研究所
;
電信研究中心
We present a novel and accurate full-wave mode-matching approach to analyze the dispersion characteristics of millimeter-wave and microwave transmission lines with finite conductivity, metallization thickness, and holding grooves. The approach is quite general but only the results for a unilateral finline are presented. The accuracy of the solution depends primarily on the correct and complete description of eigenfunction expansions in each of the uniform (stratified) or nonuniform layer regions. The latter consists of metallized strips of finite conductivity, which in turn produce the so-called metal modes (eigenmodes). The metal mode exists in the metallized region with high conductivity for the most part and decays sharply in the air region. Without incorporating the metal modes, the convergence studies will fail and the accuracy of the field theory solution deteriorates. Since the accuracy of the present approach is established, the composite effects of the finite conductivity and metallization thickness can be studied rigorously. A numerical limiting case analysis shows that the mode conversion between the dominant finline mode and the dielectric-slab-loaded waveguide mode may happen through the reduction of the metallization thickness. The theoretical results for the dispersion parameters of the dominant mode propagation constant and the characteristic impedance are reported. The effects of the conductor losses using various metallizing materials are also presented.
FULL-WAVE AND EXPERIMENTAL INVESTIGATIONS OF RESONANT AND LEAKY PHENOMENA OF MICROSTRIP STEP DISCONTINUITY PROBLEMS WITH AND WITHOUT TOP COVER
(1994)
LO, WT
;
TZUANG, CKC
;
PENG, ST
;
LIN, CH
;
傳播研究所
REFLECTION ANALYSIS FOR PLANAR SURFACE-WAVE ANTENNAS WITH DIFFERENT TAPERING PROFILES
(1995-12-01)
XU, SJ
;
PENG, ST
;
電信工程研究所
;
Institute of Communications Engineering
The reflection characteristics of the planar surface wave antennas with different tapering profiles are analyzed by a method which transforms the radiation problem into the transmission problem of the eigen mode in the partially dielectric filled planar waveguide to avoid the difficulty of the field source problem which is met in the traditional analysis. As a result, the analysis procedure is tremendously simplified. The effect of the tapering profile on the reflection property is carefully investigated and extensive numerical results are given to establish useful guidelines for the design of the planar surface wave antennas.
RESONANT PHENOMENA IN CONDUCTOR-BACKED COPLANAR WAVE-GUIDES (CBCPWS)
(1993-12-01)
LO, WT
;
TZUANG, CKC
;
PENG, ST
;
TIEN, CC
;
CHANG, CC
This paper presents a thorough and systematic investigation of resonant phenomena in conductor-backed co-planar waveguides (CBCPW's). We used a full-wave analysis first to establish benchmark results and a series of measurements have been conducted to confirm the theoretical results. As many as ten structures of different side-plane patterns were built and tested. All the test circuits exhibit many resonances over a frequency range, as measured in terms of two-port scattering parameters. Our full-wave analysis is capable of analyzing shielded guided-wave structures with finite-width substrate, and yields the scattering parameters of the coplanar waveguide circuits accounting for the overmoded-wave propagation. Finally, simple models are developed for physical understanding and interpretation of the resonant phenomena. When treating the side planes as patch resonators, we show that the resonant frequencies can be accurately estimated by this simple model. Followed by another MSL (microstrip-like) model, which considers the excitation of the first and the second MSL modes, the resonant frequencies thus obtained are also shown to be in very good agreement with measured results. By displaying the current distributions on the conductor strips in the through or resonant states of the test circuits, the MSL modes of resonances or the patch-type resonances can be clearly seen. When resonance occurs, the electromagnetic energy is confined or carried underneath the side planes and the signal energy can hardly propagate through the central signal line of the test circuit.
SCATTERING OF PLANE-WAVES BY METALLIC GRATINGS
(1994)
PENG, ST
;
SHIAO, CM
;
電信工程研究所
;
Institute of Communications Engineering
TRANSMISSION CHARACTERISTICS OF FINITE-WIDTH CONDUCTOR-BACKED COPLANAR WAVE-GUIDE
(1993-09-01)
TIEN, CC
;
TZUANG, CKC
;
PENG, ST
;
CHANG, CC
;
傳播研究所
This paper presents theoretical and experimental results for a finite-width conductor-backed coplanar waveguide (FW-CBCPW). The guiding characteristics of FW-CBCPW are investigated first by the rigorous method of mode matching. An FW-CBCPW through line is then placed within a test fixture commonly used in laboratories, and the scattering parameters of the through line are obtained theoretically by approximating the FW-CBCPW as a simple system of coupled transmission lines. Experimental results are shown to agree very well with the theoretical ones. In particular, the anomalous behavior observed in the transmission characteristic of the through line is related to the resonant phenomenon of the terminated side planes which are short-circuited at both input and output ends due to the test fixture. Finally, a technique of mode suppression in the side-plane regions is suggested for the improvement of signal transmission over a broad band of frequency spectrum. The effects of extra higher order modes on the transmission characteristics at high frequencies are also discussed.