Three-Pole Tunable Filters With Constant Bandwidth Using Mixed Combline and Split-Ring Resonators

Author

Zhiyuan Zhao ; Jiang Chen ; Lin Yang ; Kunhe Chen

Author_Institution

Inst. of Commun. Eng., PLA Univ. of Sci. & Technol., Nanjing, China

Volume

24

Issue

10

fYear

2014

fDate

Oct. 2014

Firstpage

671

Lastpage

673

Abstract

A novel three-pole tunable bandpass filter using mixed varactor-tuned combline and split-ring resonators is proposed in this letter. A tuning range of 1.1-1.88 GHz (70.9%) with an almost constant 3 dB absolute bandwidth of 90 ±8 MHz (7.4%-4.4% fractional bandwidth) is demonstrated. The filter shows its insertion loss varying from 6.8 dB to 4.3 dB and return loss better than 13.5 dB within the tuning range. The rejection levels at both the lower and upper stopbands are > 30 dB. The measured results show good agreement with the simulated ones.

Keywords

UHF filters; band-pass filters; resonator filters; tuning; varactors; band-pass filter; constant bandwidth filters; frequency 1.1 GHz to 1.88 fHz; loss 6.8 dB to 4.3 dB; mixed combline-split ring resonators; three pole tunable filters; varactor tuned combline; Bandwidth; Couplings; Frequency measurement; Microwave filters; Optical ring resonators; Transmission line measurements; Tuning; Combline resonators; constant absolute bandwidth (CABW); split-ring resonators; three-pole tunable filters; varactor-tuned;

fLanguage

English

Journal_Title

Microwave and Wireless Components Letters, IEEE

Publisher

ieee

ISSN

1531-1309

Type

jour

DOI

10.1109/LMWC.2014.2340996

Filename

6866923