公开(公告)号：US3714588A

公开(公告)日：1973-01-30

申请号：US3714588D

申请日：1970-10-13

申请人： NASA

发明人： DEBOO G ,  HEDLUND R

IPC分类号： H03H11/12 ,  H03J7/08 ,  H03B1/04

CPC分类号： H03J7/08 ,  H03H11/1291

摘要： An electronic filter which simultaneously maintains a constant bandwidth and a constant center frequency gain as the input signal frequency varies, and remains self-tuning to that center frequency over a decade range. The filter utilizes a field effect transistor (FET) as a voltage variable resistance in the bandpass frequency determining circuit. The FET is responsive to a phase detector to achieve self-tuning.