Patent ID: 7415258

Claim:
A television tuner comprising: a low-band receiving unit; a high-band receiving unit; a mixer that frequency-converts low-band television signals output from the low-band receiving unit or high-band television signals output from the high-band receiving unit; a first switching diode that couples the low-band receiving unit and the mixer to each other; a second switching diode that couples the high-band receiving unit and the mixer to each other; and a first transistor which applies a bias voltage to one end of each of the first and second switching diodes, in which an emitter is grounded and a collector is pulled up to a power supply through a resistor, and which switches ON/OFF of the first and second switching diodes so as to be opposite to each other, wherein the other end of each of the first and second switching diodes is connected to a collector of the first transistor through a first inductance element interposed therebetween, and the collector of the first transistor is connected to one end of a second inductance element, and the other end of the second inductance element is grounded in a high-frequency manner, wherein the first transistor is turned off and a series circuit composed of the first and second inductance elements is grounded in a high-frequency manner when the low-band television signals are received and wherein the first transistor is turned on and the first inductance element is grounded in a high-frequency manner when high-band television signals are received.