| 摘要 |
A television tuner includes: low-band and high-band receiving units; a mixer that frequency-converts low-band television signals from the low-band receiving unit or high-band television signals from the high-band receiving unit; first and second switching diodes that couples the low-band or high-band receiving unit and the mixer to each other, respectively; and a transistor which applies a bias voltage to one end of each of the switching diodes. The emitter of the transistor is grounded and the collector is pulled up to a power supply through a resistor. ON/OFF of the switching diodes are switched to be opposite to each other. The other end of each of the switching diodes is connected to the collector through a first inductance element. The collector of the 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.
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