De-embedding differential noise figure using the correlation of output noise waves

This paper presents a measurement technique for de-embedding the noise figure of all sorts of differential amplifiers having arbitrary common-mode rejection. It is based on the measurement of the correlation of the noise waves at the output ports of the differential amplifier. It makes use of a hybrid coupler and takes into account the phase and amplitude imbalances of the latter. Measurement results of a radio-frequency low-noise amplifier demonstrate the validity of this general technique.