An object of the present invention is to switch a television signal or an
FM broadcasting signal by a small number of active elements, to input the
switched television signal or FM broadcasting signal to an input tuning
circuit, to reduce loss in the television signal when the television
signal is received, and to reduce interference due to the FM broadcasting
signal when the television signal is received.According to the present
invention, an the first input terminal 1 is connected to the input end 6a
of the input tuning circuit 6, first and second diodes 15 and 14 are
serially connected between the second input terminal 11 and the input end
6a of the input tuning circuit 6 and are simultaneously switched on or
off, the first diode 15 is input to the input end 6a of the input tuning
circuit 6, the second diode 14 is provided at the side of the second
input terminal 11, an inductance element 12 is interposed between the
second input terminal 11 and the second diode 14, and a first capacitance
element 17 that forms a low pass filter together with the inductance
element 12 in a state when the second diode 14 is switched on, is
connected between the connection point of the first diode 15 and the
second diode 14 and a ground.