26 GHz Bandpass Filter and Duplexer Using TM11δ Mode Dielectric Resonators with High-Q Performance and Compact Configuration

Akira ENOKIHARA  Hideki NANBA  Toshiaki NAKAMURA  Kojiro OKUYAMA  Toshio ISHIZAKI  Tomoki UWANO 

Publication
IEICE TRANSACTIONS on Electronics  Vol.E86-C  No.11  pp.2283-2291
Publication Date: 2003/11/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Microwaves, Millimeter-Waves
Keyword: 
filter,  duplexer,  millimeter-wave,  TM11δ rectan-gular-mode,  dielectric resonator,  surface mount, 

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Summary: 
26 GHz bandpass filter and duplexer using TM11δ rectangular-mode dielectric cavity resonators are proposed. These have a configuration compact and suitable for mounting on circuit boards. The resonators consisting of the Ba(Mg,Ta)O3 ceramic material showed a high quality factor value of 2600, which is roughly comparable to that of conventional E-plane waveguide filters. The dielectric losses of the ceramic material were experimentally evaluated from the viewpoint of the high frequency operation and the dielectric loss tangent of 7.410-5 was observed at 20 GHz. A three-stage Tchebyscheff bandpass filter with 0.4% relative bandwidth was fabricated and the passband insertion loss was 1.7 dB. A duplexer designed with two TM11δ mode filters and a microstrip T-junction is also presented.