Thermal Noise Modeling in Passive LTI One-Ports: A Potential Approach for Nonlinear Resistor Noise Circuit Modeling

Abstract

In this work, we present a model for describing the thermal noise performance of a general linear time invariant (LTI) passive 1-port by means of two partially correlated noise sources. The inclusion of an additional source compared to the conventional 1-source noise representation of 1-ports, allows for a more complete description of the thermal noise description not only at the external terminals of the considered admittance, but also in terms of the internal noise through its real part, guaranteeing the independence of the latter from the external circuit connected to it when thermodynamic equilibrium is considered. The results of the model demonstrate that the proposed noise modeling for linear 1-ports features an additional degree of freedom in the form of the level of correlation between both sources. We propose that this finding might be of application for maintaining a linear circuit modeling of the noise generated by a resistor with a small nonlinear resistive behavior by transferring this nonlinearity to the correlation between the sources.