Patent ID: 7705692

Claim:
A high-frequency circuit for use in a dual-hand wireless communications apparatus selectively using first and second frequency bands, comprising a diplexer for sending either one of transmission signals in said first and second frequency bands to an antenna, a coupler having a primary line connected to a common end of said diplexer and a secondary line, a detector comprising a detection diode for detecting a transmission power of a high-frequency signal sent from the secondary line of said coupler, and a harmonics-suppressing circuit disposed in series between the secondary line of said coupler and said detection diode, wherein said harmonies-suppressing circuit is an attenuator circuit constituted by only one or more resistors, wherein said first frequency band is lower than said second frequency band, wherein a matching circuit constituted by a shunt inductor and a phase circuit is disposed between the secondary line of said coupler and said harmonics-suppressing circuit for impedance matching between the coupling end of said secondary line and the detection diode in said first frequency band, and wherein a difference between a detection voltage in said first frequency band and a detection voltage in said second frequency band is reduced by said matching circuit.