| 摘要 |
PROBLEM TO BE SOLVED: To provide a feedback circuit for a wireless unit that extends the dynamic range of a transmission output of the unit. SOLUTION: In the feedback circuit for the wireless unit, when a transmission output level is decreased by a changeover circuit that provides the output to an antenna without going through a power amplifier and a coupler and the output level exceeds a variable range of a variable amplifier, the output of a preamplifier is outputted directly from the antenna. When the transmission output level is decreased further, the gain of the variable amplifier is decreased. Furthermore, a switch provided to an output of an orthogonal demodulator disconnects the feedback path to correct distortion in the amplitude and the phase as its control.
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