Patent ID: 6057690
Filing Date: 2000-05-02
Classification: G01R

Abstract:
A receiver/downconverter, comprising:a UUT input;a synthesizer input;an output;a first bandpass filter;a second band pass filter;a first low pass filter;a first phase shifter, the UUT input being selectively coupled to an input of the phase shifter for additive phase noise measurement;a first mixer, a first input of the first mixer being coupled to the synthesizer input, a second input of the first mixer being selectively coupled to UUT input for absolute phase noise measurement and DMD phase noise measurement, the second input being selectively coupled to an output of first phase shifter for additive phase noise measurement, an output of the first mixer being selectively coupled to a first bandpass filter for absolute phase noise measurement, the output of the first mixer being selectively coupled to the second bandpass filter for DMD phase noise measurement, and the output of the first mixer being selectively coupled to the first low pass filter for additive phase noise measurement;a second mixer having a first input, a second input, and an output, an output of the first bandpass filter being coupled to the first input of the second mixer;a phase locked loop coupled to a second phase shifter, an output of the first bandpass filter being coupled to the phase locked loop, an output of the second phase shifter being coupled to the second input of the second mixer;a second low pass filter having an input coupled to the output of the second mixer; anda comb generator coupled to an output of the second bandpass filter, the outputs of the first low pass filter, the second lowpass filter, and the comb generator, being selectively coupled to the output of the receiver/downconverter.