Arduino network analyzer improvements

Thread Starter

Elias Leutgeb

Joined Oct 11, 2018
3
Hello, I found this project on hackaday and wanted to make some alterations to the circuit:
https://hackaday.io/project/10021-arduino-network-analyzer
1st: Use a Teensy board for faster data sampling,
2nd :use an AD9958 DDS ic instead of the AD9851 to give it two channels
These things seem fairly straight forward as an educational project (for my self) into RF circuit design.
And now my probably naive questions:
Is it possible to mix two dds Signals with different frequencies to simultaniously stimulate for instance the fundamental and the third harmonic of a quartz crystal?
And afterwards split those two signals up via a filter network to recieve those resonance frequencies via an logarithmic amplifier?
I hope this question is understandable.
And sorry, English is not my first language
 

danadak

Joined Mar 10, 2018
4,057
Is it possible to mix two dds Signals with different frequencies to simultaneously stimulate for instance the fundamental and the third harmonic of a quartz crystal?
And afterwards split those two signals up via a filter network to receive those resonance frequencies via an logarithmic amplifier?
Yes to both. You can do the mixing digitally as arbitrary wave approach (memory + DAC),
but those DDS parts best mixed analog using classic multiplier like a Gilbert cell approach
at lower freqs, other non linear approaches at the RF ranges. You can get broadband mixer
modules from RF suppliers.

As far as filtering extracting harmonics doable, but Q (BW of filter) challenges at DDS frequencies
not trivial. You are working with RF signals and layout, component selection not simple.


Regards, Dana.
 
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