On 10/31/19 6:41 AM, Yaya via Groups.Io wrote:
was wondering if the nanoVNA can somehow be used to perform IP3 and IMD measurements of a transceiver?
???? Maybe.? For measuring IMD of a receiver, you need at least 2 relatively clean signal generators, and a combiner that isolates the generators from each other so that they don't pull each other off frequency, generate intermod inside the generators, etc. Signals generated by the nanoVNA might be clean enough on some frequencies, or you might need to do some filtering to clean them up a bit.? And some IMD measurements require a modulated signal with control over the modulating frequency and modulation depth, which the nanoVNA doesn't provide.? For things like measuring the IMD of a SSB transmitter, you need a good two-tone generator, a power attenuator on the output, and once you have that you could probably measure the level of all the tones and the generated IMD signals, and do your calculations from there.? At every step you would have to do things to convince yourself that whatever intermod products you are seeing are being generated in the equipment under test, and NOT in the test equipment.? So, you MIGHT be able to use the nanoVNA for part of the equipment to do your tests, but it would probably be a fair bit of work.
Jim Allyn - N7JA