A phase noise extraction apparatus and technique that extracts phase noise induced by a component of a transmitter from a radio frequency (RF) signal and attenuates noise induced from other sources. The RF signal is digitized, modulation is removed, and the carrier is suppressed to provide a noise signal including the phase noise and the noise induced from the other sources. A complementary autocorrelation operation is applied to the noise signal to attenuate the noise from the other sources. The correlated signal is transformed into the frequency domain to generate a power spectrum of the phase noise that may be measured or displayed.