FREQUENCY CONVERTER AND COMMUNICATION EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To reduce distortion and to improve isolation characteristic in frequency converter. SOLUTION: A local oscillation signal is inputted from a Lo matching circuit 22 connected to the gate of a high-frequency transistor 11 set so that a source and a drain are the same potential in the state of DC. The converter operates as a variable resistor varying a resistance value between a source and drain according to a gate voltage. A high-frequency signal is inputted from an input matching circuit 21 connected to the source. A frequency-converted signal is transmitted through an inter-stage matching circuit 23 connected between the drain of the transistor 11 and the source of a high-frequency transistor 12. An amplitude intermediate frequency signal is outputted from an output matching circuit 24 connected to the train of the transistor 12. Since the variation of the resistance value is utilized, the leakage of a Lo signal to an IF output can be reduced and the linearity of variable resistance is high, distortion is small.