A semiconductor circuit comprises a pair of transistors (11, 12) connected commonly at their collectors and emitters having their bases for receiving a first signal and its inverted signal, respectively; a transistor (13) connected between the common emitters and the ground potential and having a base for receiving a second signal; and an output circuit having an output load (51) connected between the common collector and a supply voltage (Vcc) to receive a third signal from the common collector. For low-voltage operation, the semiconductor circuit suppresses generation of even harmonics of a local oscillation signal.
