Phase difference measuring circuit for same fundamental frequencies - mixes signal of multiple frequency of input to obtain two phase differing signals which are filtered to retain one component of each signal

摘要

The device measures the phase difference between two harmonically related signals VR1 and VR1 and is partic. useful for frequencies higher than 1 MHz. A generator (1) produces a signal VO whose frequency is approximately equal to the fundamental, a multiple, or a submultiple of the frequency of one of the signals VR1 and VR2. This signal VO is mixed with both signals VR1 and VR2 in order to produce two signals V1 and V2 whose phase difference is equal to that between signals VR1 and VR2. The signals V1 and V2 are then filtered so that one component of each is retained. Finally the difference of phase between the two signals V1 and V2 is measured. The frequency of the signals V1 and V2 is stabilised and the signals V1 and V2 are amplified after being filtered.