| 摘要 |
PROBLEM TO BE SOLVED: To provide a mixer circuit that suppresses a DC offset of an output signal with high precision, and outputs a high quality output signal with reduced distortion.SOLUTION: A mixer circuit 18 of a frequency conversion device 10 includes two double balanced mixers (DBMs) 42, 46 each including two pairs of transistors (Mc-Mj) and operable individually, and the DBM 42 and the DBM 46 operate in combination as a single double balanced mixer having a voltage amplification gain amounting to the sum of voltage amplification gains of the DBMs 42, 46. For DC offset detection, the mixer circuit operates the DBMs 42, 46 to produce a large voltage amplification gain. As for frequency conversion, the mixer circuit uses one of the DBMs 42, 46 to suppress a frequency conversion gain and produce a high quality output signal with reduced distortion. |
