| 摘要 |
PURPOSE:To improve the detection output characteristic and the distortion characteristic by controlling the gain of a multiplier by a signal obtained by detecting an AM component produced with the amplitude characteristic of a single tuning circuit provided with a phase shifter. CONSTITUTION:An FM intermediate frequency signal obtained at an output of the phase shifter 1 having the single tuning circuit and the original intermediate frequency signal are applied to the multiplier 3. Further, the AM component produced by the amplitude characteristic of the single tuning circuit is detected by a detector 5. Then, an output of the detector 5 is given to a control input of a variable current source 7 via an inverting circuit 6 to control the gain of the multiplier 3. |
