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Spectrum Analyzer in fmcomms2

Question asked by gensysco on Jul 5, 2016
Latest reply on Jul 18, 2016 by mhennerich



We are working on an application for Cognitive Spectrum Sensing. We are newbies. For this targeted application we are looking into Analog Devices's AD9361 along with your spectrum analyzer application environment running on embedded Linux.

We have been referring to the wiki pages for your documentation for Spectrum Analyzer application. Unfortunately, the documentation is limited and we would like to get more insights into the clarity of the parameters that have been utilized.

Please address the following questions listed below:


1. What is resolution bandwidth (RBW) here and how does it impact the sweep time of a spectrum?


2. Can you explain with an example the end-to-end data flow in the zed board setup running in spectrum analyzer mode:  If I wish to scan from 1 GHz to 6 GHz with RBW  of 1 MHz,  How does the sampling rate for ADC is set, the decimation filters are set, the calibration factors are set? Also, how is the FFT size decided?


3. Is RF bandwidth different from Resolution BW (RBW) the same? If not, then how are they different?


4. Is FFT is being performed on RBW or RF Bandwidth of the signal chip is seeing?


5. How can we calculate the time taken for a single complete scan of the desired spectrum? In one of our application the requirement for time is stringent. Which parameters will be impacted/modified/changed when we wish to reduce the overall time ?


Thanks a lot in advance.

Best Regards,