摘要 |
A baseband signal processing circuit for a radio communication apparatus has an amplifier for amplifying the amplitude of an input baseband signal, a limiter for limiting the amplitude of the amplified baseband signal, an amplitude detector for detecting the amplitude of the output signal of the amplifier, and a control unit for controlling the gain of the amplifier in response to the output of the amplitude detector. When the amplitude detector detects an amplitude greater than predetermined one, the control unit controls the gain of the amplifier in such a manner as to maintain the output of the amplifier at a constant level. As a result, the output level of the amplifier is prevented from exceeding the limiter level of the limiter. This allows the maximum frequency transition to be set up with no regard to frequency and suppresses distortions regarding signals exceeding the standard frequency transition.
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