Browsing by Author "LO, WT"

Now showing 1 - 4 of 4

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
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.
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.