| 摘要 |
<p>A television tuner includes an input tuning circuit (3) and an interstage tuning circuit (9). Each of the tuning circuits comprises a band-switching tuning circuit (7) having a tuning inductor (3a-d) and a switching diode (3f) for switching an inductance of the inductor. A power supply voltage is applied to the anode of each of the switching diodes via each of anode-side feed resistors (5), the anode being DC-grounded via current-conducting means (4). A tuning frequency band of each of the input tuning circuit and the interstage tuning circuit is switched by applying a high or low level switching voltage to the cathode of each of the switching diodes via each of cathode-side feed resistors. <IMAGE></p> |
