FREQUENCY CONVERSION CIRCUIT, GAIN CONTROL CIRCUIT OF FET AMPLIFIER USED THEREFOR, AND GAIN CONTROL METHOD OF FET AMPLIFIER

摘要

PPROBLEM TO BE SOLVED: To suppress a dynamic range required for a variable attenuator inserted in the middle of a multi-step FET amplification part which amplifies the level of RF signal that is a conversion output to a desired value, relating to a frequency conversion circuit, and to suppress increase in the number of FET amplifier elements. PSOLUTION: The frequency conversion circuit comprises a frequency conversion part 101 which converts frequency of an input signal, a multi-step FET amplification part 102 for amplifying the frequency conversion output, a variable attenuator (V-ATT) which varies the signal level inserted into the signal path from the frequency conversion part to the output of the multi-step FET amplification part. It is characterized by comprising a gate voltage control part 103 which controls a gate voltage of FETs of the multi-step FET amplification part 102 based on the frequency information according to the frequency of the frequency conversion output and the temperature information based on a temperature. PCOPYRIGHT: (C)2009,JPO&INPIT