ADRF5730 Attenuation Accuracy

I think that you need to take the following approach. Download the s-parameters from analog.com. The header in all of the files say that the reference plane is the edge of the device. On your side, you need to model your pcb traces, that is, simulate your trace design and derive its s-parameters. Then you need to put together both sets of s-parameters to see what net insertion loss you see. Load the s-parameters for the various attenuation states and see how the attenuation looks compared to what it should be. Because the DSA's s-parameter data will change slightly with attenuation setting, there will be  variance in the matching across all of the  attenuation/s-param_file states. If the variance is unacceptable at some states, the best you can do is to try and find a match design that will give you the best attenuation accuracy across all states. 

I think that you need to take the following approach. Download the s-parameters from analog.com. The header in all of the files say that the reference plane is the edge of the device. On your side, you need to model your pcb traces, that is, simulate your trace design and derive its s-parameters. Then you need to put together both sets of s-parameters to see what net insertion loss you see. Load the s-parameters for the various attenuation states and see how the attenuation looks compared to what it should be. Because the DSA's s-parameter data will change slightly with attenuation setting, there will be  variance in the matching across all of the  attenuation/s-param_file states. If the variance is unacceptable at some states, the best you can do is to try and find a match design that will give you the best attenuation accuracy across all states.