Slight frequency deviation when demodulating the TX via RX

#1 · 01/11/2022, 11:12

I connected the TX output to the RX input and tried to demodulate a single tone signal

with the IQ demodulator and plot it with the IQ oscilloscope. However, the IQ signal is beating at roughly

2 Hz even though set the same frequency for the tone and IQ demodulation frequency. As I understand, the TX and RX share the same

clock source, thus there should not be any frequency deviations. Did I overlook something? Is it possible to get a stable phase IQ signal somehow?

Thank you very much in advance.

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#2 · 07/11/2022, 15:34

Looks like a deviation between PC clock and internal SPECTRAN V6 clock. We will check it.