High-frequency circuit and communications apparatus comprising same
AssigneeHitachi Metals, Ltd.
InventorsKeisuke Fukamachi, Shigeru Kemmochi
Life of this patent
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Abstract
A high-frequency circuit for use in a dual-band wireless communications apparatus selectively using first and second frequency bands, comprising a diplexer connected to the output of a power amplifier for sending either one of transmission signals in the first and second frequency bands to an antenna, a coupler having a primary line connected to a common end of the 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 the coupler, and a harmonics-suppressing circuit disposed between the secondary line of the coupler and the detection diode.
Claims6
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.
A high-frequency circuit for use in a dual-band 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 harmonics-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 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.
A high-frequency circuit for use in a dual-band 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 comprising one or more antenna ends,
- 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 harmonics-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, and wherein a matching 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.
Dependencies are inferred from the claim text.