Frequency-fluctuating interference removed receiver

In order to efficiently and steadily remove a frequency-fluctuating interference wave, for instance, a leakage wave of a household electronic oven, intermixed into a received wave for communication, adaptively to the frequency deviation and the frequency fluctuation of the interference wave, a rejection band component included in the received wave applied onto a circulator, an output terminal of which is connected with a variable band rejection filter, is reflected from the output terminal on which impedance mismatch is caused by zero-impedance presented by the rejection filter on the basis of absorption of the input wave and applied to a detector through the circulator again, in response to a detection output of which a so-called peak-keeping control is effected on the variable band rejection filter for shifting the rejection band, so as to maximize the detection output of the detector adaptively to the frequency deviation and the frequency fluctuation of the interference wave.