I’m interested in a description of the precise method for measuring the Lime SDR XTRX TX output power to confirm its specifications (0-10 dBm). The frequency range of interest is 2000-2800 MHz. For the test harmonic signal, it was not possible to obtain an output power greater than -3.9 dBm at 2300 MHz.
You might find this report by Alexandru Csete and Sheila Christiansen from SDR Makerspace helpful:
They only test a LimeSDR-Mini, not an XTRX, although I wouldn’t expect too much difference in Tx performance. I think they have slightly different RF matching and switching designs. They measured about 0 dBm output for a gain of 60 dB at 2250 MHz (Fig 2.64). Note that they did come to the conclusion that their LimeSDR-Mini might have been broken (based on very poor Rx performance) so take that number with a pinch of salt.
If you do replicate their experiments with an XTRX it would be great if you could share!
Cheers,
Iain