| 摘要 |
PROBLEM TO BE SOLVED: To allow a small-sized mobile radio equipment which is light weight to accurately detect a receiving signal strength indicator(RSSI) output signal which denotes a reception level. SOLUTION: A signal converted into an intermediate frequency is fed to a demodulation signal processing circuit via a gain variable circuit 108, an active filter circuit 109 and a limiter circuit 111. A detector 120 detects an output of each stage of the limiter circuit 111, and an adder 113 sums the output to obtain an RSSI output signal corresponding to a reception level via a low- pass filter 114. A control signal of a level detection circuit 110 that detects a control signal of the gain variable circuit 108 limiting an input signal of the active filter circuit 109 is fed to the adder 113 via a coefficient multiplier 115 for enhancing the linearity of the RSSI output signal with respect to a reception level. |
