A novel impedance pattern for fast noise measurements

Complete noise characterization of an active device implies the extraction of the minimum noise figure (F/sub min/), noise resistance (R/sub n/), and optimum value of the complex input reflection coefficient (/spl Gamma//sub opt/). Such quantities can be obtained through a minimum of four noise figure measurements, associated to four different reflection coefficients at the input of the DUT, (/spl Gamma//sub in,k/ k = 1 /spl middot/ /spl middot/ /spl middot/ 4), forming an "impedance pattern." Measurement redundancy is usually required to reduce overall uncertainty, therefore forcing one to use, for the synthesis of a large number of different terminations, an impedance tuner. This paper introduces a novel four-points input pattern, which becomes an "optimum" trade-off between accuracy and complexity, while avoiding the use of a tuner: a drastic reduction in cost and complexity of the measurement bench therefore results.