公开(公告)号：US4356568A

公开(公告)日：1982-10-26

申请号：US918513

申请日：1978-06-23

申请人： Minoru Ogita ,  Naobumi Kimura

发明人： Minoru Ogita ,  Naobumi Kimura

IPC分类号： H04B1/26 ,  H03G5/24 ,  H03G5/28 ,  H04B1/10 ,  H04H1/00 ,  H04H40/72 ,  H04B1/16

CPC分类号： H04H40/72 ,  H03G5/24 ,  H03G5/28 ,  H04B1/1027

摘要： A receptive condition automatic selection device for an FM receiver comprises a band width changing circuit for changing a band width of an intermediate-frequency amplifier of the receiver, a first detector for detecting a noise level contained in a demodulation signal from a demodulator, a second detector for detecting a tuning condition of the receiver by the demodulation signal and a bistable circuit connected to said first and second detectors for producing a control signal for the band width changing circuit. The band width of the intermediate-frequency amplifier can be automatically changed to either a narrow band or a wide band in accordance with receptive conditions of the FM receiver.

摘要翻译： 用于FM接收机的接收状态自动选择装置包括用于改变接收机的中频放大器的带宽的带宽改变电路，用于检测来自解调器的解调信号中包含的噪声电平的第一检测器，第二 检测器，用于通过解调信号检测接收机的调谐状态;连接到所述第一和第二检测器的双稳态电路，用于产生用于带宽改变电路的控制信号。 根据FM接收机的接收条件，中频放大器的带宽可以自动改变为窄带或宽带。