摘要 |
A negative feedback amplifier has input portions for receiving input signals, adder circuits, a quadrature modulator for performing a quadrature modulation on outputs of the adder circuits, a first signal level variable control circuit for adjusting a level of an output signal from the quadrature modulator, an amplifier circuit for amplifying an output of the first signal level variable control circuit, a feedback circuit for negative feedbacking an output of the negative feedback circuit to the adder circuit, and a second control circuit for controlling an adjusting amount in the first signal level variable control circuit based on the output signal levels of the adder circuits so that the output signal levels of the adder circuits becomes predetermined values. The feedback circuit includes a first control circuit for controlling a signal level of the feedback circuit so that the output signal level of the amplifier circuit becomes a predetermined value.
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