| 摘要 |
A tuner in which a band switching signal corresponding to a channel selected from a plurality of UHF and VHF bands is generated to enable the formation of a suitable resonant circuit for receiving television signals of the selected channel. It includes a varactor diode, a plurality of resonant coils and distribution constant lines which are each grounded at one end. Each of the coils and the line is provided for forming a resonant circuit for tuning one of the bands. A plurality of switching diodes are provided for connecting the other ends of the coils and the line selectively to the other end of the varactor diode. The tuner further includes a device for turning on and off the switching diodes selectively in response to the band switching signal.
|
