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FMCOMMS1 TX DAC bandwidth and waveform sampling

Question asked by drg on Mar 24, 2014
Latest reply on Apr 9, 2014 by drg

I am currently working with the ZC706 and FMCOMMS1 on the Linux boot image (build-2014-03-13).

 

My goal is to transmit a wideband waveform similar to a stepped chirp with approximately 7 truncated step frequencies. I have been successful generating baseband waveforms within Matlab, outputting to a text file, and transmitting the waveform via the IIO oscilloscope application. I soon hope to interface with the DAC buffer using the Linux drivers within my own application or shell scripting. If necessary, I could transition to the no-OS drivers.

 

My question is in regard to the bandwidth and sampling with AD9122. The bandwidth I am currently able to produce is slightly less than what is needed for my application without distortion and need a higher sampling rate. It seems IIO is using an interpolation factor of 2x when my DAC sampling frequency is set to 491.52MHz. I would like to output a waveform closer to 175MHz bandwidth. I believe the AD9122 should be able to acheive a 200MHz BW. What is necessary to change the interpolation factor to 1x or increase the sampling frequency using the linux drivers?

 

Thank you for your help.

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