A Measurement of Noise Wave Correlation Matrix Using Noise Power Ratios

In this paper, we propose a novel technique for the measurement of noise wave correlation matrix (NWCM) of a two-port network using measured noise power ratios. The ratio of two measured noise powers is observed to show significantly reduced fluctuations compared with absolutely measured noise powers. Based on this observation, the equations to compute the NWCM are formulated using the noise power ratios. Since the NWCM has four unknowns, five absolute output noise powers of a device under test (DUT) are measured to obtain four noise power ratios. The conventional noise parameters can then be obtained by converting the NWCM. In order to demonstrate this technique, we measured the NWCM of an active DUT with a noise figure of less than 1 dB. The noise parameters resulting from the measured NWCM show minimal fluctuations as expected.