Patent ID: 7181186

Claim:
A frequency conversion apparatus for correcting phase mismatching of first and second IF signals in response to an RF input signal transmitted through an RF input terminal, said apparatus comprising: a quadrature signal generator (QSG) for outputting a first oscillating frequency signal and a second oscillating frequency signal differing in phase from the first oscillating frequency signal; a first mixer for mixing the RF input signal with the first oscillating frequency signal and an inverted signal of the second oscillating frequency signal to generate a first IF signal; and a second mixer for mixing the RF signal with the second oscillating frequency signal and the first oscillating frequency signal to generate a second IF signal; wherein the first mixer comprises: a first switching unit for switching on/off the RF input signal according to the first oscillating frequency signal; and a second switching unit coupled to the RF input terminal parallel to the first switching unit for switching on/off the RF input signal according to the inverted signal of the second oscillating frequency signal; and wherein the second mixer comprises: a third switching unit for switching on/off the RF input signal according to the second oscillating frequency signal; and a fourth switching unit coupled to the RF input terminal parallel to the third switching unit for switching on/off the RF input signal according to the first oscillating frequency signal.