| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmission circuit in which current consumption is reduced in response to a transmission output with a wide dynamic range. SOLUTION: This transmission circuit has an orthogonal modulator 3, a gain control amplifier 4, an up-mixer 7, a driver amplifier 8, a power amplifier 9 and an antenna 10 and is configured so as to generate a transmission output of a wide range. In this case, there are provided with a 1st switch 12 that bypasses an input signal of the driver amplifier 8, a 2nd switch 10 that bypasses an input signal of the power amplifier 9 and a controller 18 that applies on/off control to a power supply of the driver amplifier 8 and the power amplifier 9 to generate a control signal for the gain control amplifier 4, the 1st switch 12 and the 2nd switch 13. A current at a low transmission output is reduced by conducting the gain control of the gain control amplifier 4 depending on the transmission output, bypass control of the input signal to the power amplifier 9 and the driver amplifier 8, and power on/off control of the power amplifier 9 and the driver amplifier 8. |
