Patent ID: 6774739
Filing Date: 2004-08-10
Classification: H03D

Abstract:
A frequency converter to which an input signal, a local oscillation signal and a reference direct current signal are supplied, the frequency converter comprising:a variable gain amplifier which amplifies the local oscillation signal according to a gain control signal and outputs an amplified local signal; an even harmonic mixer which is supplied with the input signal and the amplified local oscillation signal and outputs an output signal whose frequency is a sum 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 or a difference between the first frequency and the second frequency; an amplitude detector 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 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.