Abstract: The noise performance of a non-linear circuit design is measured prior to circuit fabrication by a circuit modelling and analysis mechanism, which simulates each noise source as a reduced complexity continuous Gaussian noise waveform. A respective noise source (e.g. thermal or shot) is modelled as a time domain sequence of continuously connected third order polynomial signal waveforms, forming a cubic spline that interconnects successively occurring Gaussian signal amplitude values. For each type of noise source, its associated Gaussian function is determined by the product of the constant multipliers associated with that type of source. The number of points processed for each noise source depends upon the time width of a noise analysis window.

Abstract: An auto-biasing virtual circuit mechanism for a bipolar transistor is independent of the biasing and the configuration of a signal waveform application circuit in which the transistor is installed. The virtual circuit comprises a plurality of AC signal coupling elements (capacitors) coupled in circuit between respective ones of a plurality of AC signal access terminals and respective ones of the base, collector and emitter electrodes of the transistor. Because of their frequency dependent impedance characteristics, each coupling capacitor effectively provides a short circuit coupling path for AC signals, while blocking or being an open circuit for DC bias inputs. Conversely, DC biasing is effected through large valued inductors, which provide short circuit coupling paths for DC bias inputs, while blocking or being open circuits for AC signal conditions.