Frequency doubling of a quadrature-amplitude modulated signal using a frequency multiplier

摘要

A method and system of frequency multiplying a signal having amplitude modulation using a frequency multiplier operated at a bias voltage that is less than its saturation mode voltage is described. Prior to amplification, the amplitude modulated signal is pre-distorted to compensate for distortion caused by the frequency multiplier. A first pre-distortion phase converts the amplitude modulated signal into a corresponding square root signal to compensate for a first distortion type. A second pre-distortion phase pre-distorts the square root signal to compensate for the distortion caused by biasing the frequency multiplier at a voltage less than the saturation voltage of the multiplier. As a result, a signal that is amplitude modulated can be multiplied by a frequency multiplier.