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Noise Characterization of Multiport Amplifiers



James P. Randa


I address the issue of the definition and measurement of noise figure and parameters to characterize multiport devices, particularly differential amplifiers. A parameterization in terms of the noise matrix appears to be the most practical. the noise figure for a given output port is defined and related to the noise matrix and scattering parameters of the device. Two examples are considered in detail: a 3-port differential amplifier and a 4-port mixed-mode amplifier, both with reflectionless terminations. The noise figures, effective input temperatures, and gains are related to the results of a series of hot-cold measurements, as in the familiar two-port case.
IEEE Transactions on Microwave Theory and Techniques


amplifier noise, differential amplifier, multiport amplifier, noise, noise figure, noise matrix, thermal noise


Randa, J. (2001), Noise Characterization of Multiport Amplifiers, IEEE Transactions on Microwave Theory and Techniques, [online], (Accessed April 19, 2024)
Created October 1, 2001, Updated January 27, 2020