Receiving circuit

Abstract

A receiving circuit mainly available in a digital modulation type communication system having a plurality of channels, which is capable of reducing power in a receiving system, simplifying the circuit and reducing the power consumption. Upside and downside frequencies corresponding to a central value between channels are separately supplied from a local frequency signal generating circuit,to first and second frequency converting circuits,so that two output signals are developed with respect to one of a desired wave, upside channel and downside channel. The desired wave present in common in the first and second frequency converting circuits,is extracted in a common wave extracting circuit,, and a frequency offset of &ohgr;o existing in the output of the common wave extracting circuit,is removed a frequency offset circuit,and further an unnecessary frequency component is filtered by a filter,. In addition, the common wave extracting circuit,has transformers and, using its inductances, raises the difference between the common wave and the non-common wave within the circuit to more than two times that of a prior art.