| 摘要 |
In an antenna matching circuit switching system of a portable telephone, an antenna transmits a transmission signal and receives a reception signal in form of electromagnetic wave. A receiving section receives the reception signal from the antenna and a transmission section supplies the antenna with the transmission signal having a first frequency which is different from a second frequency of the reception signal. A transmission and reception switching section connects the antenna to the receiving section in response to a reception control signal and to the transmission section in response to a transmission control signal. A first antenna matching circuit is matched to the antenna in the second frequency, and a second antenna matching circuit is matched to the antenna in the first frequency. An antenna matching circuit switching section connects the antenna to the first antenna matching circuit in response to the reception control signal and to the second antenna matching circuit in response to the transmission control signal. A control section selectively issues the reception control signal and the transmission control signal to the transmission and reception switching section and the antenna matching circuit switching section.
|
