Using High Performance Spectrum Analyzer to Measure Residual AM of Signal Generator

The traditional method of measuring the residual AM is to use modulator analyzer or measuring receiver with the function of demodulation option to measure it directly for its simplicity and convenience. This paper interprets the definition of residual AM and proposed the way that is using to measure the residual AM with the condition that PSA once has fairly low displayed average noise level, good resolution bandwidth switching uncertainty and absolute amplitude accuracy .The example is given that how to measure the residual AM of signal of Agilent 8648C signal generators using Agilent E4447A PSA. Evaluation and expression of uncertainty in the measurement of residual AM are also showed. Contracted with Agilent 8902 measuring receiver with the function of demodulation option, using high performance PSA to measure the residual AM is available.