公开(公告)号：US4145659A

公开(公告)日：1979-03-20

申请号：US800422

申请日：1977-05-25

申请人： Adolf E. Wolfram

发明人： Adolf E. Wolfram

IPC分类号： H03J3/06 ,  H03J3/18 ,  H04B1/26

CPC分类号： H03J3/06 ,  H03J3/185

摘要： A high input selectivity UHF varactor tuner for a television receiver in which unamplified radio frequency signals are inductively coupled to a double tuned half-wave preselector comprising two aperture coupled half-wave tuned lines in separate resonant cavities. The double tuned preselector includes varactor diodes on one end of each tuned line and fixed capacitors on the other end of each line. To compensate for decreasing Q of the varactor diodes with decreasing frequency and thereby maintain a uniform bandwidth for the tuner over the entire UHF spectrum, inductive coupling is provided between the tuned lines at the fixed capacitor ends which, during low frequency operation of the tuner, augments aperture coupling between the lines.

摘要翻译： 用于电视接收机的高输入选择性UHF变容二极管调谐器，其中非放大射频信号电感耦合到双调谐半波预选器，其包括在分离的谐振腔中的两个孔耦合半波调谐线。 双调谐预选器包括每个调谐线的一端的变容二极管和每条线的另一端的固定电容器。 为了补偿频率降低的变容二极管的Q减小，从而在整个UHF频谱上保持调谐器的均匀带宽，在固定电容器端的调谐线路之间提供电感耦合，在调谐器的低频操作期间， 增加线路之间的孔径耦合。