ELECTRONIC TUNER, HIGH-FREQUENCY SIGNAL RECEIVER USING THE SAME, AND CONTROL METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide an inexpensive electronic tuner by employing an electronic switch for transmitting high frequency signals without employing a conventional analog switch etc. using an MOSFET for transmitting an analog voltage transmitting a DC minute voltage change. SOLUTION: The electronic tuner is provided with an attenuation amount selecting circuit 40 for selecting an attenuation amount by an electronic switch 39 connected to an output of an intermediate frequency amplifier 29 and transmitting high frequency signals, and a detector 38 connected between this selecting circuit 40 and a gain control terminal 24a of a high-frequency amplifier 24. In each of cases where a digital broadcast signal 52 is received and where an analog broadcast signal 51 is received, the selecting circuit 40 performs control for switching an attenuation amount based on a signal to be output from a PLL circuit 46. COPYRIGHT: (C)2007,JPO&INPIT