I'm doing work comparing measurements of modulation from a DUT against a reference modulation source. The same instrument is used to generate the carrier for each. Both look a lot like square pulses at about 160 kHz around carriers near 900 MHz. For each modulation source, I'm measuring amplitude between the two states (e.g. (delta I)^2 + (delta Q)^2) with the Basic measurement personality on a PSA at 8 MHz. I'd like to think that this is nearly as simple as a modulation measurement could get My question is, if we can assume both the DUT and reference modulation are ideal square waves, does anyone know of a good way to estimate a relative accuracy of the measurement of the amplitude comparing these two signals?
Please refer to the PSA Specifications guide: http://cp.literature.agilent.com/litweb ... -90644.pdf
The relative linearity and relative fidelity (see page 70 of the specifications guide) for the Spectrum Analysis mode can be used as a guide for what the linearity would be in the Basic mode. Also, when measuring within 20 dB of the noise floor, you need to include the effect of the analyzer’s noise on the measurement. The effect of noise is given in footnote b on page 69 of the specifications guide.
Regards -