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How to control a signal generated by DDS with a feedback loop?

Question asked by MaPa on Feb 25, 2011
Latest reply on Feb 28, 2011 by Georgy

Hi,

I will soon start a project with the following setup/requirements:

 

A sine-wave signal is generated by a DDS chip with given frequency (variable between 1kHz and 100 kHz), phase and amplitude. So far so good.

This signal gets further amplified, transmitted and finally received, again. Due to temperature drifts, controlling phase and amplitude is required. For this purpose, the receive signal will be used in a feedback loop. The receive signal differs in amplitude and phase from the transmit signal, which is given by the system itself.

 

Question:

What is the propper way to detect the exact phase and amplitude of the receive signal at the transmit frequency?

My first idea: quadrature detection

I guess, I'm not the first with this kind of setup. Is there a reference design available? Any suggestions? Any different ideas?

 

Thank you very much.

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