TY - JOUR AU1 - Lin, Jenshan AU2 - Chang, Chi-Yang AU3 - Yamamoto, Yukio AU4 - Itoh, Tatsuo AB - A review of a tunable active bandpass filter developed in our research group is given here. Presented first is the basic structure of an end-coupled microstrip-line bandpass filter. Next discussed is the concept of using coupled negative resistance to compensate the loss of tank circuit. Then, the method of using varactor diode or mesfet varactor to tune the center frequency of the passband is discussed. The capability of optical-control of mesfet varactor and the concept of using mesfets as three-terminal varactors are also discussed. TI - Progress of a tunable active bandpass filter JF - Annals of Telecommunications DO - 10.1007/bf02998312 DA - 1992-11-01 UR - https://www.deepdyve.com/lp/springer-journals/progress-of-a-tunable-active-bandpass-filter-9hQT0she3R SP - 499 EP - 507 VL - 47 IS - 11-12 DP - DeepDyve ER -