A broadband tunable combline filter using active devices

Author

Lockerbie, Ian ; Kumar, Surinder

Author_Institution

Dept. of Electr. Eng., Saskatchewan Univ., Saskatoon, Sask., Canada

fYear

1993

fDate

6/15/1905 12:00:00 AM

Firstpage

196

Lastpage

200

Abstract

Electronically tunable microwave filters with fast tuning speed can be realized using varactor tuned combline microstrip structures. Even when GaAs varactors are employed, the resonator Q is limited by the varactor losses and the filter bandwidth has to be more than 8-10%. The authors present a solution to the problem. The varactor losses are compensated by coupling a negative resistor in the tuned circuit. This resistor is realized using an active device. Computer simulation results for a filter with 3% bandwidth are presented. Performance results with and without the negative resistance are presented to bring out improvement due to negative resistance.

Keywords

compensation; equivalent circuits; losses; microstrip components; microwave filters; negative resistance; tuning; varactors; GaAs; active devices; broadband; electronic tuning; fast tuning speed; microstrip structures; microwave filters; negative resistance; tunable combline filter; tuned circuit; varactor; varactor losses; Active filters; Bandwidth; Gallium arsenide; Microstrip filters; Microwave devices; Microwave filters; Resistors; Resonator filters; Tunable circuits and devices; Varactors;

fLanguage

English

Publisher

ieee

Conference_Titel

WESCANEX 93. 'Communications, Computers and Power in the Modern Environment.' Conference Proceedings., IEEE

Conference_Location

Saskatoon, Sask., Canada

Print_ISBN

0-7803-1319-4

Type

conf

DOI

10.1109/WESCAN.1993.270574

Filename

270574