Title :
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
fDate :
8/1/2009 12:00:00 AM
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;
Journal_Title :
Microwaves, Antennas & Propagation, IET
DOI :
10.1049/iet-map.2008.0308
