Recommendations and comments:

1. This setup can also be used for gain and P1dB, if desired
2. For wideband measurements, the 30-dB gain stage and 10-dB attenuators are used to improve the input IP3 level that is created from the interaction of the 2 signal generators via the isolation of the combiner. For narrow band measurements, it maybe possible to create a setup with enough isolation using an isolator and/or combiner. In this case the 10-dB pads could be reduced or removed.
3. Power meter A is used to ensure the amplitude of the two tones at the input of the TRF37x73/75 EVM are within a certain tolerance. The gain stages will have unique gain characteristics and their gain can drift over time
4. Power meter B can be used for measuring the amplitude of individual tones for more accurate measurements.
5. Keep spectrum analyzer RBW and VBW settings identical for main tone and IM3 products
6. Take into account losses of coax and attenuators to and from the EVM board
7. Take into account losses of traces on the board up to the I/O pins of the DUT