Patent ID: 7024170

Claim:
A frequency conversion apparatus for converting the frequency of an outer input signal in which element signals having a predetermined frequency bandwidth are sequentially arranged in a predetermined frequency interval, comprising: frequency conversion sections of the same number as said element signals, each of said frequency conversion sections comprising: a first oscillator and a second oscillator both being capable of presetting the frequencies of signals output therefrom; a first frequency mixer for mixing the output signal of said first oscillator with said outer input signal to output a signal, the frequency of said signal being converted from the frequency of the outer input signal; a first filter for extracting a signal having a predetermined frequency bandwidth from the output signals of said first frequency mixer; a second frequency mixer for mixing the output signal of said second oscillator with the output signal of said first filter to output a signal, the frequency of said signal being converted from the frequency of the output signal of said first filter; and a second filter for extracting a signal having a predetermined frequency bandwidth from the output signals of said second frequency mixer; and a synthesizer for synthesizing the respective output signals from said frequency conversion sections to form an output signal, wherein the respective frequencies of said first and second oscillators are determined in accordance with a predetermined frequency setting rule specified by the relationship between said frequency conversion sections in conjunction with (1) a desired center frequency of the output signal of said second filter in a respective one of the frequency conversion sections and a center frequency of a respective one of the element signals in said outer input signal, or (2) a fixed interval between the center frequencies of the respective element signals in said outer input signal, and a desired fixed interval between the center frequencies of the respective output signals from said second filters.