|NI RF Vector Signal Transceivers 18.1Help|
|NI RF Vector Signal Transceivers 18.2.1 Help|
|NI RF Vector Signal Transceivers 19.1 Help|
The RF IN signal path chooses gain and attenuation settings based on the requested reference level. The gain definition measured in calibration is adjusted and applied according to the following equation:
RF Input Gain (dB) = Complex PowerADC (dB) – Real PowerRF IN Terminal (dB)
The resulting gain scales the acquired data to reference back to the RF IN front panel connector. The reported gain scales both I and Q evenly. This scaling results in a 3 dB shift from the expected value. Apply a –3 dB offset to the resulting power spectrum or FFT to normalize to the real power expected at the RF IN front panel connector.