one-port circuit with negative resistance
equivalent source of noise
A bipolar transistor with two capacitors switched between collector-emitter and emitter-base connectors can be represented as a one-port circuit with negative resistance. The inner transistor and circuit elements noise sources were represented as a one equivalent source of noise switched with an active one-port circuit. The relations for calculation of its spectral characteristics were given. The dependence for noise characteristics from a working regime, frequency, and device parameters are represented. There were suggested expressions for calculations the spectral density of noise currency by the nonlinear one-port circuit.
Change of correspondence between cophased and quadrature components of noise are detected at variation of the cut-off angle. Recommendation for reducing the onepoint circuit noise. Simplified expressions allowing evaluation of the spectral density for the reduced noise current of the active one-pole circuit, with accuracy sufficient for engineering practice, are proposed.