Title :
Theoretical and experimental investigation of novel varactor-tuned switchable microstrip ring resonator circuits
Author :
Martin, T. Scott ; Wang, Fuchen ; Chang, Kai
Author_Institution :
Dept. of Electr. Eng., Texas A&M Univ., College Station, TX, USA
Abstract :
A microstrip ring resonator circuit loaded with two p-i-n diodes has been developed for use as a switchable filter. By replacing one p-i-n diode with a varactor diode, the switchable filter can be made electronically tunable. Isolation exceeding 20 dB with 9% tuning bandwidth was demonstrated. An analysis based on transmission line theory was used to model both circuits. The analysis includes the effects of diode parasitics, coupling gaps, dispersion, and mounting-gap capacitance. The experimental results agree very well with the theoretical calculation.<>
Keywords :
distributed parameter networks; equivalent circuits; linear network analysis; microwave filters; p-i-n diodes; passive filters; resonators; solid-state microwave circuits; strip line components; switched filters; transmission line theory; tuning; varactors; PIN diode loading; band-pass filters; band-reject type; coupling gaps; diode parasitics; dispersion; electronically tunable; microstrip ring resonator circuits; microwave filters; mounting-gap capacitance; p-i-n diodes; switchable filter; transmission line theory; varactor diode tuning; Bandwidth; Circuit optimization; Microstrip filters; Microstrip resonators; Optical ring resonators; P-i-n diodes; Resonator filters; Switching circuits; Tunable circuits and devices; Varactors;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
