Patent ID: 6121840
Filing Date: 2000-09-19
Classification: H03F

Abstract:
A high-frequency amplifier for matching both a lower-band high-frequency signal and a higher-band high-frequency signal, comprising:an amplifying circuit having an input and an output;an input circuit and an output circuit;an input matching circuit connected between the input of said amplifying circuit and the input circuit; andan output matching circuit connected between the output of said amplifying circuit and the output circuit,wherein said input circuit includes an input terminal, an input coupling capacitor connected in series between said input terminal and said input matching circuit,wherein said input matching circuit includes an input matching capacitor connected to said input circuit, said input matching capacitor being separate from said input coupling capacitor, a first inductor connected between said input matching capacitor and said amplifying circuit, and a second inductor connected to the connection point of said capacitor and said first inductor,wherein said input matching capacitor and said second inductor form a lower-band frequency matching circuit for achieving matching for a lower-band high-frequency signal, andsaid first inductor forms a higher-band frequency matching circuit for achieving matching for a higher-band high-frequency signal which is higher in frequency than said lower-band high-frequency signal.