Patent ID: 6311049
Filing Date: 2001-10-30
Classification: H03G

Abstract:
A mobile radio receiver, comprising:a variable gain circuit for controlling in response to a control signal a level of an intermediate frequency signal derived from a received signal to provide a variable gain output signal;an active filter, to which the variable gain output signal is input, for extracting said intermediate frequency signal to produce an active filter output signal;a multistage limiter for wave-shaping the active filter output signal;a level detector for detecting an output level of said active filter output signal and producing said control signal fed back to control a gain of said variable gain circuit, wherein when the output level of said active filter output signal exceeds a predetermined level said control signal is increased to maintain the output signal level of said variable gain circuit at a constant level;a plurality of detectors for detecting signal level components at respective stages of said multistage limiter and for producing a respective plurality of detector output signals;a coefficient multiplier receiving said control signal for multiplying said control signal by a predetermined coefficient to produce a coefficient multiplier output signal; andan adder for summing the plurality of detector output signals and the coefficient multiplier output signal being fed forward and producing a receiving signal strength indicator as a sum thereof.