| 摘要 |
PURPOSE: To optimally control entire efficiency by optimally setting the bias conditions of a drive stage amplifier even when the gain of a final amplifier is changed by any temperature change at the power amplifier. CONSTITUTION: A drive stage amplifier 2 and a final stage amplifier 3 are serially connected. The input part and output part of the final stage FET amplifier 3 are respectively equipped with level detection parts 5 and 6, and this amplifier provided with a power supply circuit 8 for controlling a voltage to be supplied to the drain terminal of the FET amplifier 2 on drive stage and a control circuit 7 for changing the output voltage of the power supply circuit 8 while receiving the output level and input level of the final stage amplifier 3. |
