Cancellation of Amplitude-to-Phase Noise Conversion by Adjusting Sweet Point of the Mixer

SummaryMixer is usually used as the phase discriminator in a frequency transfer system, of which characteristics are directly related to the stability of the transfered signal. This experiment verifies the system characteristics of amplitude and phase noise conversion in mixers. The output noise of the mixer are minimum when two inputed signals are nearly orthogonal, which is called the Sweet Point. Compared with other cases, amplitude fluctuations at Sweet Point can be reduced by an order of magnitude and the measured instability can be improved.