Patent ID: 6393372
Filing Date: 2002-05-21
Classification: G01R

Abstract:
A noise measurement test system for making phase noise measurements of signals produced from a unit under test (UUT) having a UUT input and a UUT output, said noise measurement test system comprising:a variable amplifier having an amplifier input for receiving signals from a unit under test and an amplifier output for coupling to a mixer; a variable low noise source for producing a low noise signal, said low noise source including a splitter for splitting said low noise signal into a first low noise carrier signal for being output from a first output and a second low noise signal for being output from a second output, said first output for coupling to a UUT input and said second output for coupling to a variable phase shifter; a variable phase shifter including a phase shifter input coupled to said second output of said low noise source and a phase shifter output for coupling to a mixer, said variable phase shifter for adjusting the phase of said second low noise signal received from said second output of said low noise source; a mixer including first and second mixer inputs and a mixer output, said first mixer input coupled to said amplifier output, said second mixer input coupled to said phase shifter output and said mixer output for coupled to a processor, said mixer including a synchronous phase detector for synchronizing signals received at said first and second inputs for outputting a measurement test signal from said mixer output; and a processor including a processor input coupled to said mixer output, said processor also including control links for connecting said processor to said amplifier, said low noise source and said phase shifter for automatically controlling the adjustments of said amplifier, said low noise source and said phase shifter.