FREQUENCY CONVERTER, ORTHOGONAL DEMODULATOR AND ORTHOGONAL MODULATOR

摘要

PROBLEM TO BE SOLVED: To provide a frequency converter that can utilize features of an even harmonic mixer with less sensitivity deterioration due to self-mixing without increasing number of components. SOLUTION: The frequency converter comprises a variable gain amplifier 102 which amplifies the local oscillation signal according to a gain control signal and outputs an amplified local signal, an even harmonic mixer 101 which is supplied with an input signal and an amplified local oscillation signal and outputs an output signal whose frequency is a sum or a difference of a first frequency of the input signal and a second frequency of two or more even numbered times a frequency of the amplified local oscillation signal, an amplitude detector 103 which is supplied with the amplified local oscillation signal and outputs a direct current signal having an amplitude corresponding to an amplitude of the amplified local oscillation signal, and a comparator 104 which compares the direct current signal of the amplitude detector with the reference direct current signal to generate an output signal as the gain control signal.