Title :
A broadband tunable combline filter using active devices
Author :
Lockerbie, Ian ; Kumar, Surinder
Author_Institution :
Dept. of Electr. Eng., Saskatchewan Univ., Saskatoon, Sask., Canada
fDate :
6/15/1905 12:00:00 AM
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;
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
DOI :
10.1109/WESCAN.1993.270574
