[G0HZU_JMR]

The Marki IMD test setup is very comprehensive, and I doubt many people use a setup with all those diplexers. The Marki setup is designed to measure the mixer in an ideal environment where there are no constructive/destructive port reflections anywhere. They need to avoid these reflections in order to put a valid result on their datasheet for that mixer. That's why they have that impressive test setup.

Even if you did replicate their setup, the IMD result you are really interested in is the result when the mixer is fitted in your receiver design and not when it is in Marki's ideal test rig. depending on your circuit, the mixer IP3 could be degraded quite a bit compared to the result achieved using the Marki setup.

Usually, the mixer input IP3 is about 12-15dB higher than the input P1dB for a regular diode ring mixer. The input P1dB is about 6dB lower than the LO drive level.

Therefore, a classic LO Level 7dBm mixer like the SBL-1 could be expected to have an input P1dB of +1dBm and an input IP3 of about +15dBm. However, if the mixer circuit has poor IF port match at the image frequency, then this IP3 measurement will often be degraded. It's also possible to deliberately mismatch the IF port at the image frequency in such a way that the image reflection is constructive. This might improve the conversion loss for example. Usually, a poorly terminated IF port makes the IP3 performance notably worse than expected.