High-frequency amplifier having simple circuit structure and television tuner using high-frequency amplifier

A high-frequency amplifier comprising:

• a first amplifying stage and a second amplifying stage that are disposed in parallel and that amplify VHF/UHF television signals received through an antenna,
• the first amplifying stage comprising:
• a first FET and a second FET that are of a grounded-gate type and that are connected in series between a common input terminal and a first output terminal to which a VHF-signal selection circuit is connected, and
• the second amplifying stage comprising:
• a third FET and a fourth FET that are of a grounded-gate type and that are connected in series between the common input terminal and a second output terminal to which a UHF-signal selection circuit is connected,
• wherein switching between amplifying operations of the first and second amplifying stages is performed by an operation switching unit selectively setting one of the first and third FETs in a forward-bias state and the other of the first and third FETs in a reverse-bias state in response to a switching voltage that is externally set.