AnsweredAssumed Answered

AD9361 receive chain maximum SNR/SFDR

Question asked by mike.ericson on Oct 28, 2015
Latest reply on Oct 28, 2015 by tlili

Hi,

 

What AD9361 receive chain settings yield the maximum SNR and SFDR without using any of the on-chip RX FIR filters?

 

I have experimented with the FMCOMMS3-EBZ board and I'm able to achieve 60+ dBc ACPR using a 5 MHz wideband signal without using any of the on-chip TX FIR filters when looking at the AD9361 transmitter output on a signal analyzer.  However, when I loop this signal back to the AD9361 receiver input, I can't get the ACPR to be any better than the high 40's without using one of the on-chip RX FIR filters.

 

I've tried lots of combinations of automatic gain control, manual gain control, external amplification, and external attenuation, but, unless I use one of the on-chip RX FIR filters, I can't receive a signal of the same quality that I can transmit without using any on-chip TX FIR filters.

 

Is this expected?

 

Thanks,

Mike

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