Browsing by Author "TZUANG, CKC"

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A FULL-WAVE MIXED POTENTIAL MODE-MATCHING METHOD FOR THE ANALYSIS OF PLANAR OR QUASI-PLANAR TRANSMISSION-LINES
(1991-10-01)
TZUANG, CKC
;
TSENG, JD
;
傳播研究所
;
友訊交大聯合研發中心
;
Institute of Communication Studies
A newly proposed and tested full-wave mixed potential mode-matching method is presented for the analysis of planar and/or quasi-planar transmission lines. The transmission lines under investigation consist of layered (stratified) and nonlayered dielectric substrates and metal strips of finite thickness. The y-directed hybrid TE and TM Hertzian potentials, perpendicular to the interfaces between each layered regions, are employed in the layered regions. The nonlayered regions, which consist of dielectric step discontinuities that destroy the layered configuration in the horizontal plane, utilize the x-directed hybrid TE and TM Hertzian potentials parallel to the horizontal plane. As a direct result, the full-wave formulation of the transmission line problem becomes systematic and easy to handle. Extensive analyses of a particular case study show that the relative convergence criterion needs to be satisfied to obtain accurate electromagnetic field solutions. The theoretical results obtained here are in very good agreement with the published data for various transmission line structures, which are the special limiting cases of the particular case study. The applications of the new formulation to the proximity effects of microstrip and Microslab1 lines are also illustrated by examples.
A TERMINATION SCHEME FOR HIGH-SPEED PULSE-PROPAGATION ON A SYSTEM OF TIGHTLY COUPLED COPLANAR STRIPS
(1994-06-01)
KUO, JT
;
TZUANG, CKC
;
傳播研究所
;
電信工程研究所
;
Institute of Communication Studies
A realistic termination scheme is proposed for closely coupled N-conductor microstrips. The design aims to achieve satisfactorily low signal reflection and good fabrication feasibility for the planar MMIC (Monolithic Microwave Integrated Circuit) process. The matched termination network (MTN) for a lossless three-line coupled microstrip structure is presented. High-speed pulse transmission along terminated tightly coupled microstrip lines is analyzed using modal analysis in the frequency domain. Theoretical results for the propagating and reflected waveforms are obtained by applying the inverse discrete Fourier transform (IDFT) to the system responses. These responses are obtained by applying the theory of multiconductor transmission lines to a dispersive database which has been computed using the spectral-domain approach (SDA). The response of a six-line closely coupled microstrip circuit terminated by the proposed termination scheme is measured using the HP8510D network analyzer. The measured results show that the reflected signal is below -30 dB and the results are in good agreement with the theoretical waveforms.
ANALYSIS AND DESIGN OF FEEDING STRUCTURES FOR MICROSTRIP LEAKY WAVE ANTENNA
(1995)
LIN, YD
;
SHEEN, JW
;
TZUANG, CKC
;
傳播研究所
;
Institute of Communication Studies
CHARACTERISTICS OF DIELECTRIC-LINE-LOADED CONDUCTOR-BACKED SLOTLINE (CBS)
(1994-07-01)
HUANG, JW
;
TZUANG, CKC
;
交大名義發表
;
傳播研究所
;
National Chiao Tung University
The mode-coupling phenomenon prevents the conventional shielded conductor-backed slotline (CBS) from broadband applications. This paper proposes a modified CBS by adding a dielectric line of higher dielectric constant on the top of the dot region to circumvent the mode-coupling problem. The dispersion characteristics of the resultant dielectric line-loaded CBS are studied by using the full-wave space-domain Green's impedance. function approach. The theoretic results show that the particular modified CBS significantly reduces mode-coupling phenomenon and is suitable for broadband applications. Furthermore, it is possible to adjust the values of the propagation constant and the characteristic impedance by changing the thickness of the dielectric line on top of the slot region. Finally, the design curves for the dielectric line-loaded CBS are provided for potential applications.
COMPLEX LEAKY WAVES OF A PARTIALLY OPEN NONRECIPROCAL SLOTINE ON GYROMAGNETIC SUBSTRATE
(1994)
TZUANG, CKC
;
FUH, KF
;
MROZOWSKI, M
;
傳播研究所
;
Institute of Communication Studies
COMPLEX-MODES IN SHIELDED SUSPENDED COUPLED MICROSTRIP LINES
(1990-09-01)
KUO, JT
;
TZUANG, CKC
;
電信工程研究所
;
電子與資訊研究中心
;
Institute of Communications Engineering
DESIGN OF A 3-DIMENSIONAL GAP-COUPLED SUSPENDED SUBSTRATE STRIPLINE BANDPASS FILTER
(1992-08-01)
CHIANG, YC
;
TZUANG, CKC
;
SU, S
;
交大名義發表
;
電信工程研究所
A three-dimensional gap-coupled suspended substrate stripline (SSS) bandpass filter, based on the modified configuration of the classic end-coupled filter, is presented. it consists of printed half-wavelength resonators placed on the same and/or the opposite sides of the suspended substrate. These resonators orient themselves in arbitrary directions. Such an arrangment makes the new filter highly flexible to interface with other microwave subcircuit modules. The filter is constructed in a bent channelised housing that suppresses any possibility of exciting higher-order modes, except the dominant quasi-TEM mode of propagation. Consequently, the channelised filter is free from any coupling between itself and other microwave circuit components within the system. Two look-up tables, derived from a variational three-dimensional quasi-TEM spectral-domain analysis of the discontinuity problems associated with the adjacent gap-coupled resonators, are incorporated into the computer-aided design of the new filter. The de-embedded discontinuity parameters are validated by comparing them with those obtained by experiment and full-wave approaches for the microstrip open-end and the SSS end-coupled problems, respectively. The measured results for the experimental 21-22 GHz bandpass filter agree very well with the theoretic predictions considering the conductor losses (5.57 x 10(-3) dB/mm) of the SSS. It has less than 1.4 dB insertion loss and greater than 10 dB return loss in the passband.
EFFECT OF FINITE SUBSTRATE WIDTH ON HIGHER-ORDER MODE GENERATION OF ELECTRICALLY SHIELDED SYMMETRICAL MICROSTRIP
(1992-01-16)
TSENG, JD
;
TZUANG, CKC
;
交大名義發表
;
電信研究中心
;
National Chiao Tung University
The effect of finite substrate width on the higher-order mode generation of an electrically shielded microstrip is investigated. By employing the full-wave mixed potential mode-matching method the microstrip on a finite-width substrate can be accurately analysed. The dispersion characteristics of microstrip on two different substrate widths were compared in the frequency range of interest. The results indicated that the use of conventional three-dimensional simulators assuming homogeneous layered (stratified) multi-dielectric substrates may not work well above the first cutoff frequency of microstrip on a finite-width substrate.
EFFECT OF LATERAL WALLS ON THE PROPAGATION CHARACTERISTICS OF FINITE-WIDTH CONDUCTOR-BACKED COPLANAR WAVE-GUIDES
(1993-07-22)
TIEN, CC
;
TZUANG, CKC
;
MONROE, J
;
傳播研究所
;
Institute of Communication Studies
The connection of the side planes of finite-width conductor-backed coplanar waveguide (FW-CBCPW) to the ground through lateral walls suppresses the undesired microstrip-like (MSL) mode and provides a wide frequency range over which singlemode propagation occurs. The leakage or resonance phenomena of the higher-order modes can be avoided, if the distance separating the lateral walls is carefully designed.
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
GREENS IMPEDANCE FUNCTION-APPROACH FOR PROPAGATION CHARACTERISTICS OF GENERALIZED STRIPLINES AND SLOTLINES ON NONLAYERED SUBSTRATES
(1994-12-01)
HUANG, JW
;
TZUANG, CKC
;
交大名義發表
;
電信工程研究所
;
National Chiao Tung University
A newly proposed generalized full-wave space-domain integral equation technique incorporating dyadic Green's impedance function and a new set of basis functions are presented for the analysis of striplines and slotlines arbitrarily integrated on multiple nonlayered sustrates. The generalized full-wave integral equation technique is validated by conducting convergence study and several case studies. The theoretical dispersion characteristic of the transmission lines obtained here are in very good agreement with the published and measured data for the modified Microslab and the microstrip proximity effect near substrate edge. For the slotline type problem, where a new set of current basis function must be derived to be incorperated into Green's impendance function approach, the new approach presented here shows that the corresponding propagation characteristics thus obtained are also in excellent agreement with those reported in the available literature, which normally used the slot electric fields as the unknowns. To explain bow general the present formulation is, it can be reduced to the well-known spectral domain formulation for any guided-wave structure containing only layered substrates.
K-BAND QUASI-PLANAR TAPPED COMBLINE FILTER AND DIPLEXER
(1993-02-01)
LO, WT
;
TZUANG, CKC
;
交大名義發表
;
電信工程研究所
;
National Chiao Tung University
The quasi-planar realizations of combline bandpass filter and diplexer using multiple coupled suspended substrate striplines (MCSSS's) have demonstrated good performance at K-band without any tuning. The N MCSSS's excite N zero-cutoff-frequency quasi-TEM modes. A new computer-aided filter design approach employing rigorous SDA (spectral-domain-approach) and 2N-port microwave circuit theory accounts for the effects of the N quasi-TEM modes, the couplings through non-adjacent MCSSS's, and cover height. Two 19.5-to-20.5 GHz MCSSS's combline filters with different cover heights are built and tested to compare their filter characteristics. The reduction in cover height decreases the amount of non-adjacent couplings through MCSSS's and results in better filter stopband performance. Another 18.5-to-19 GHz and 20-to-20.5 GHz MCSSS's diplexer is also presented. All the measured results for the combline filters and diplexer agree well with the theoretic calculations.
K-BAND SUSPENDED SUBSTRATE STRIPLINE TAPPED COMBLINE FILTER
(1991-07-18)
LO, WT
;
TZUANG, CKC
;
交大名義發表
;
傳播研究所
;
National Chiao Tung University
A newly developed 19.5-20.5 GHz combline bandpass filter realised by multiple coupled suspended substrate striplines (MCSSSs) and metal-insulator-metal (MIM) capacitors is presented. The filter design uses an iterative field-theory-based algorithm to account for the composite effects of multiple dominant quasi-TEM modes of the MCSSS and the couplings through the nonadjacent lines. A prototype is built and tested. The measured and theoretical filter characteristics are in good agreement for the combline filter without any tuning.
MAGNETICALLY SCANNABLE MICROSTRIP ANTENNA EMPLOYING A LEAKY GYROMAGNETIC MICROSTRIP LINE
(1995-08-03)
FUH, KF
;
TZUANG, CKC
;
交大名義發表
;
電信工程研究所
;
National Chiao Tung University
Rigorous full-wave spectral-domain analyses of a magnetically scannable gyromagnetic microstrip leaky-wave antenna are presented. Varying the DC magnetic bias field by similar to 6.5%, the maximum radiation angle of the leaky-wave antenna, measured from the horizon, shifts from zero to almost 90 degrees.
MODAL CURRENT DISTRIBUTIONS ON CLOSELY COUPLED MICROSTRIP LINES - A COMPARATIVE-STUDY OF THE SDA BASIS FUNCTIONS
(1990-03-29)
TZUANG, CKC
;
KUO, JT
;
交大名義發表
;
傳播研究所
;
National Chiao Tung University
MODE-COUPLING-AVOIDANCE OF SHIELDED CONDUCTOR-BACKED COPLANAR WAVE-GUIDE (CBCPW) USING DIELECTRIC LINES COMPENSATION
(1994)
HUANG, JW
;
TZUANG, CKC
;
傳播研究所
;
Institute of Communication Studies
ON THE MODE-COUPLING FORMATION OF COMPLEX-MODES IN A NONRECIPROCAL FINLINE
(1993-08-01)
TZUANG, CKC
;
LIN, JM
;
傳播研究所
;
電控工程研究所
;
友訊交大聯合研發中心
This paper studies and models the mechanism for forming the complex modes commonly found in boxed quasi-planar or planar guided-wave structures. To illustrate the fact that the mode-coupling among the various forms of modes is closely related to the formation of complex modes, the dispersion characteristics of the complex propagation constants (or the so-called mode spectrum) of a nonreciprocal unilateral finline are obtained by the rigorous full-wave SDA (spectral-domain approach). It is found that in the mode spectrum of the nonreciprocal finline, a forward wave and a backward wave interact to produce a pair of complex modes. The interactions between two forward (backward) traveling waves, between a forward wave and a backward wave, and between two complex waves (modes) are modeled by applying the model-coupling theory. The concept of hypothetical modes is introduced in the model. These hypothetical modes are obtained by applying mode-coupling theory to the mode spectrum previously obtained. The approximate values obtained for the propagation constants of the three types of wave interactions using the model presented in the paper are in close agreement with those given by the full-wave SDA.
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.
RIGOROUS DISPERSIVE ANALYSIS OF SKIN EFFECTS ON A PRINTED MICROSTRIP LINE CONTAINING FINITE CONDUCTOR LOSSES
(1990-08-16)
TZUANG, CKC
;
WANG, WK
;
交大名義發表
;
傳播研究所
;
National Chiao Tung University