Load Line Analysis and Fourier Series

Summary

The v‐i characteristic of a nonlinear resistor such as a diode or a transistor is often described by a curve on the v‐i plane rather than by a mathematical relation. The v‐i characteristic curve can be obtained by using a curve tracer for nonlinear resistors. To analyze circuits containing a nonlinear resistor, a user should use the load line analysis. Since Thevenin and Norton equivalents are equivalent in representing a linear circuit seen from a pair of two terminals, one can be obtained from the other by using the source transformation. According to the theory on Fourier series, any practical periodic function can be represented as a sum of (infinitely) many trigonometric (cosine/sine) functions or complex exponential functions, which is called the Fourier series representation. There are four forms of Fourier series representation as follows: trigonometric form; magnitude‐and‐phase form; complex exponential form; and effects of vertical/horizontal translations of function on the Fourier coefficients.