| 摘要 |
A transmitter section of a mobile telephone set of a cellular telephone system includes a high-frequency signal oscillator, a modulator, a variable gain amplifier, a power amplifier, an antenna duplexer, and an antenna. Two high-frequency signal changeover switches are respectively provided upstream and downstream of the power amplifier. In transmitting a signal at a low output power, the power amplifier is turned off and the two changeover switches cause a high-frequency signal to go through a bypass line, that is, bypass the power amplifier. Thus, transmitter power control with a wide dynamic range can be attained while the power consumption is greatly reduced.
|
