Читать книгу Handbook of Microwave Component Measurements - Joel P. Dunsmore - Страница 109

The LO distribution attributes are critical in the performance of mixer‐based systems. The phase noise of the LO contributes directly to errors (primarily trace noise) in the phase of the measured signal. Even the trace noise of the amplitude response can be degraded by phase noise as the signal moves across the IF bandwidth filter. Providing a common and coherent LO to all the mixers improves the trace noise of the measurement by allowing the effects of LO phase noise to be reduced when the measured parameter is a ratio, such as gain or return loss.