Development of Millimeter-Wave Planar Diplexers Based on Complementary Characters of Dual-Mode Substrate Integrated Waveguide Filters With Circular and Elliptic Cavities

Author

Tang, Hong Jun ; Hong, Wei ; Chen, Ji-Xin ; Luo, Guo Qing ; Wu, Ke

Author_Institution

Dept. of Radio Eng., Southeast Univ., Nanjing

Volume

55

Issue

4

fYear

2007

fDate

4/1/2007 12:00:00 AM

Firstpage

776

Lastpage

782

Abstract

A novel high-performance millimeter-wave planar diplexer is developed based on the complementary characters of substrate integrated waveguide (SIW) dual-mode filters with circular and elliptic cavities by making the tradeoff between the isolation, insertion loss, and selectivity. The responses of the dual-mode SIW circular and elliptic cavities are first investigated. It can be found that the upper side response of the circular cavity and the lower side response of the elliptic cavity are very steep. The diplexers with high isolation performance are then designed based on the complementary response characters of circular and elliptic cavities. A diplexer with two dual-mode SIW circular and elliptic cavities is designed and fabricated with a normal printed circuit board process. The measured insertion losses are 1.95 and 2.09 dB in the upper and lower passbands centered at 26 and 25 GHz with the fractional bandwidths of 5.2% and 5.4%. The isolation is lower than - 50dB

Keywords

microwave filters; millimetre wave filters; multiplexing equipment; planar waveguides; printed circuits; waveguide filters; 1.95 dB; 2.09 dB; 25 GHz; 26 GHz; circular cavities; complementary response characters; dual-mode filters; elliptic cavities; high isolation performance; millimeter-wave planar diplexers; printed circuit board process; substrate integrated waveguide filters; Coplanar waveguides; Dielectric losses; Filters; Insertion loss; Microstrip; Millimeter wave communication; Millimeter wave technology; Planar waveguides; Printed circuits; Waveguide transitions; Circular cavity; diplexer; dual-mode filter; elliptic cavity; substrate integrated waveguide (SIW);

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/TMTT.2007.893655

Filename

4148123