Tunable slotted ground structured bandstop filter with BST varactors

YH Chun, JS Hong, P Bao, Timothy Jackson, Michael Lancaster

Research output: Contribution to journalArticle

20 Citations (Scopus)


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.
Original languageEnglish
Pages (from-to)870-876
Number of pages7
JournalIET Microwaves Antennas & Propagation
Issue number5
Publication statusPublished - 1 Aug 2009


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