Patent ID: 7885632

Claim:
A noise test measurement system configured to measure a noise component of a transmitted RF signal, comprising: an antenna for receiving the transmitted RF signal to provide a received RF signal; a low-noise amplifier configured to amplify the received RF signal to provide an amplified RF signal; a local oscillator configured to provide an LO signal; a first coupler configured to combine a first version of the LO signal with the amplified RF signal to provide a combined RF signal; a first variable phase-shifter configured to phase-shift a second version of the LO signal into a quadrature LO signal responsive to a control signal; a first mixer having an RF port configured to receive the combined RF signal and an LO port configured to receive the quadrature LO signal, the first mixer being further configured to mix the signals received at its RF and LO ports to provide a first mixed output signal; and a processor configured to analyze a digitized version of the first mixed output signal so as to produce the control signal and to measure the noise component.