FREQUENCY CONVERSION APPARATUS FOR IMPROVING AMPLITUDE-MISMATCHING

摘要

A frequency conversion apparatus with improved amplitude mismatching is provided to improve a signal-to-noise ratio by eliminating the amplitude mismatching of two oscillating frequency signals having a phase difference of 90 degrees. A frequency convertor(100) mixes two reference frequency signals to output an I signal and a Q signal. A comparator(200) compares amplitudes of the I and Q signals. An amplitude adjustor(300) varies the amplitudes of the I and Q signals according to the compared results. The frequency converter has an orthogonal signal generator(110) for generating first and second oscillating frequency signals and first and the second mixers(120,130) for composing the first and the second oscillating frequency signals. The orthogonal signal generator has an oscillator for outputting the first oscillating frequency signal and a phase shifter(112) for shifting a phase of the first oscillating frequency signal to output the second oscillating frequency signal.