Patent ID: 6480006
Filing Date: 2002-11-12
Classification: G01R

Abstract:
A method for measuring absolute, DMD and additive phase noise using a low noise synthesizer, comprising the steps of:providing a receiver/downconverter including a UUT input and an output, selectively coupling the UUT input to an input of a first phase shifter for additive phase noise measurement, passing a signal from the low noise synthesizer to a first mixer, selectively coupling the first mixer to the UUT input for absolute phase noise measurement and DMD phase noise measurement and to an output of the first phase shifter for additive phase noise measurement, selectively coupling an output of the first mixer to a first bandpass filter for absolute phase noise measurement, to a second bandpass filter for DMD phase noise measurement and to a first low pass filter for additive phase noise measurement, passing a signal from the first bandpass filter to a second mixer and to a phase locked loop coupled to a second phase shifter, passing a signal from the second phase shifter to the second mixer, passing a signal from the second mixer to a second low pass filter, passing a signal from the second bandpass filter to a first comb generator, and selectively coupling outputs of the first low pass filter, the second low pass filter and the first comb generator, to the output of the receiver/downconverter.