K-band quasi-planar tapped combline filter and diplexer

Author

Lo, Wen-Teng ; Tzuang, Ching-Kuang C.

Author_Institution

Inst. of Electr. Commun. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan

Volume

41

Issue

2

fYear

1993

fDate

2/1/1993 12:00:00 AM

Firstpage

215

Lastpage

223

Abstract

Quasi-planar realizations of a combline bandpass filter and diplexer using multiple coupled suspended substrate striplines (MCSSSs) have demonstrated good performance at K-band without any tuning. The N MCSSSs excite N zero-cutoff-frequency quasi-TEM modes. A computer-aided filter design approach employing a rigorous spectral domain approach and 2N-port microwave circuit theory accounts for the effects of the N quasi-TEM modes, the couplings through nonadjacent MCSSSs, and cover height. Two 19.5-20.5 GHz MCSSS combline filters with different cover heights have been built and tested to compare their filter characteristics. The reduction in cover height has been found to decrease the amount of nonadjacent coupling through MCSSSs and to result in better filter stopband performance. An 18.5-19 GHz and 20-20.5 GHz MCSSS diplexer is also presented. All the measured results for the combline filters and diplexers agree well with the theoretic calculations

Keywords

band-pass filters; microwave filters; passive filters; strip line components; 18.5 to 20.5 GHz; 2N-port microwave circuit theory; K-band; SHF; bandpass filter; computer-aided filter design; cover heights; diplexer; multiple coupled suspended substrate striplines; quasi-TEM modes; quasiplanar realisation; spectral domain; tapped combline filter; Band pass filters; Bars; Circuit optimization; Coupling circuits; Fasteners; Frequency; K-band; Microwave filters; Resonator filters; Stripline;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.216459

Filename

216459