SEMICONDUCTOR INTEGRATED CIRCUIT FOR FREQUENCY CONVERSION

摘要

PROBLEM TO BE SOLVED: To improve the frequency conversion gain by suppressing increase in an impedance caused by a parasitic inductance between a source electrode of a field effect transistor(FET) and a point of a ground potential without adoption of an expensive capacitor using a ferroelectrics. SOLUTION: In this integrated circuit, a source electrode a FET 2 is connected to a point of a ground potential via a ground potential point connecting terminal 18. In this case, an external capacitor 30 whose capacitance is, e.g. 200pF-1000pF is connected to the integrated circuit 1 in order to reduce the impedance at a low frequency mainly by a parasitic inductance 23 in existence between a source electrode of the FET 2 and the ground potential point, and an internal capacitor 31 whose capacitance is, e.g. 30pF-50pF is formed in the integrated circuit 1 in order to reduce a high frequency impedance caused by parasitic inductive components 23, 32. Thus, a low impedance characteristic over a broad frequency band and an excellent conversion gain are obtained.