An analytic design method for microstrip tunable filters

Ju Seop Lee, Kamal Sarabandi

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

This paper describes an analytic design procedure for microstrip tunable filters. Step-impedance resonators are employed and loaded with varactors for achieving agility in the filter response. Fixed lumped capacitors are utilized as admittance inverters in order to minimize the number of varactors in the filter. An analytic approach for filter design makes it possible to achieve a tunable filter showing the same frequency response when the center frequency is adjusted. A two-pole microstrip tunable filter whose center frequency can be adjusted from 1.1 to 1.5 GHz is designed to demonstrate the validity of design theory. A prototype tunable filter operating from 2.1 to 2.7 GHz is also designed and measured. A good agreement between the measured and simulated results is shown. Finally, three- and four-pole tunable filters are designed to show straightforward application of the presented design method to higher order tunable filter design.

Original languageEnglish
Article number4545889
Pages (from-to)1699-1706
Number of pages8
JournalIEEE Transactions on Microwave Theory and Techniques
Volume56
Issue number7
DOIs
Publication statusPublished - 2008 Jul 1
Externally publishedYes

Fingerprint

tunable filters
Poles
Varactors
varactor diodes
poles
filters
inverters
Frequency response
Resonators
electrical impedance
Capacitors
frequency response
capacitors
resonators
prototypes
impedance

Keywords

  • Microwave filters
  • Tunable filters
  • Varactor

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this

An analytic design method for microstrip tunable filters. / Lee, Ju Seop; Sarabandi, Kamal.

In: IEEE Transactions on Microwave Theory and Techniques, Vol. 56, No. 7, 4545889, 01.07.2008, p. 1699-1706.

Research output: Contribution to journalArticle

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