System Variable
Quantitative variables describe the relationship between input and output when that relationship is not a straight line. Every non linear parameter in a system model requires specific identification through curve fitting or iterative optimization. These values dictate how the gain or response changes as the signal amplitude increases.
Component Characteristic
Electronic devices like transistors and diodes exhibit characteristics that depend on the operating point. A non linear parameter such as the transconductance coefficient or the junction capacitance varies according to the bias voltage. Accurate simulation relies on extracting these values from measured data sets.
Harmonic Effect
Energy transfers into different frequency bands when a signal passes through a non linear stage. The magnitude of a non linear parameter determines the strength of the second and third order harmonics produced by the circuit. In power amplifiers, these values are used to predict the adjacent channel interference levels.
Total harmonic distortion increases when the input signal swings into the non linear regions of the transfer function.
Characterization Method
Multi tone testing reveals how the system handles complex waveforms. A non linear parameter is often verified by measuring the intermodulation products at varying power levels. These tests define the compression point where the output starts to saturate.
