Tunable slotted ground structured bandstop filter with BST varactors

Author

Chun, Y.-H. ; Hong, Jing-Song ; Bao, Paul ; Jackson, Thomas J. ; Lancaster, Michael J.

Author_Institution

Dept. of Electr., Electron. & Comput. Eng., Heriot-Watt Univ., Edinburgh

Volume

3

Issue

5

fYear

2009

fDate

8/1/2009 12:00:00 AM

Firstpage

870

Lastpage

876

Abstract

This paper presents an investigation of a tunable bandstop filter (BSF) using slotted ground structure. A kind of open loop slot resonator is used for the bandstop response and its characteristics according to various dimensions are considered to decide a proper shape for the final design. A barium-strontium-titanate (BST) varactor chip is deployed to tune each resonator and its location is determined by electromagnetic simulation for an optimum frequency tuning. A three-pole tunable BSF of this type is measured at the centre frequency from 4.5 to 5.5 GHz and its rejection is more than 20 dB at the stop band while the insertion loss at the pass band is less than 1.5 dB.

Keywords

barium compounds; microwave filters; resonators; strontium compounds; varactors; BST varactors; barium-strontium-titanate varactor chip; electromagnetic simulation; frequency 4.5 GHz to 5.5 GHz; insertion loss; open loop slot resonator; optimum frequency tuning; slotted ground structure; tunable slotted ground structured bandstop filter;

fLanguage

English

Journal_Title

Microwaves, Antennas & Propagation, IET

Publisher

iet

ISSN

1751-8725

Type

jour

DOI

10.1049/iet-map.2008.0308

Filename

5161699