Dear Sir:

There exists a relationship between time delay and phase and I would like to know exactly how my network analyzer measures phase for S11 measurements. Specifically, how does the network analyzer (8753C) know the exact time [ when ] to sample the reflected signal for a S11 measurement?

Enclosed is snapshot of a measurement taken of a GR900 connector for explanatory purposes. I used the electrical delay feature and dialed back to obtain 369.21 pS just to show that a specific time delay time is associated with a phase measurement. At zero degrees, there is a baseline time delay measurement, I would like to know how does this time delay time arise at this specific point, also, how does the NA calculate when to take the time sample of the reflected signal?

I need to verify the phase measurements that my network analyzer is measuring for metrological purposes and I need to verify that my network analzyer is operating correctly, can you please answer these two questions.

There exists a relationship between time delay and phase and I would like to know exactly how my network analyzer measures phase for S11 measurements. Specifically, how does the network analyzer (8753C) know the exact time [ when ] to sample the reflected signal for a S11 measurement?

Enclosed is snapshot of a measurement taken of a GR900 connector for explanatory purposes. I used the electrical delay feature and dialed back to obtain 369.21 pS just to show that a specific time delay time is associated with a phase measurement. At zero degrees, there is a baseline time delay measurement, I would like to know how does this time delay time arise at this specific point, also, how does the NA calculate when to take the time sample of the reflected signal?

I need to verify the phase measurements that my network analyzer is measuring for metrological purposes and I need to verify that my network analzyer is operating correctly, can you please answer these two questions.

The phase of S11 is determined frequency by frequency, comparing the phase in the IF of the R channel with the phase of the IF in the A channel. Since A and R receivers are driven the be the same choherent LO, their relative phase response is stationary with respect to sweep to sweep variations. THe LO and the source will both vary, the R channel is used to remove the variation through normalization of the ratio S11_raw=A/R. A receiver measures the reflected signal.

There is a systematic offset in the raw phase of A and R; this is removed by measuring known standards. There is not timing associated with this measurement. Any time computation is strictly mathmatically derived from the the frequency data. Thus, if you add 1 nsec of delay, the display is mathematically changed by delay=delta_phase/(360*frequency); but this is all post measurement, there is no change in any of the stimulus or measurement conditions.