| 摘要 |
PURPOSE:To obtain an electronic tuning-system receiver which operates stably even if a strong electric field is inputted. CONSTITUTION:An input signal passes through tuning circuit 1 and is mixed with the output of local oscillator circuit 4 by mixer circuit 3, and the sum or difference frequency output becomes the output of IF input 5. In the tuning circuit, varactor diodes 9 and 12 are biased reversely to use the depletion layer capacity of varactor diodes as the capacity of the tuning circuit, thereby determining the tuning frequency. Then, capacitors 14 and 15 are connected in parallel to varactor diodes 9 and 12, and selector switch 16 which interlocks with a receiving band selector switch is equipped. |
