Driving Point Impedance and Signal Flow Graph Basics: A Systematic Approach to Circuit Analysis

Abstract

The driving point impedance/signal flow graph (DPI/SFG) methodology is based on fundamental analysis techniques—equivalent circuits and superposition, which along with a direct mapping of circuit relations onto a signal flow graph results in a direct and systematic analysis process. Following this approach leads to factored solutions for direct manipulation of the design to produce a desired shaping of the design response. The DPI approach divides the analysis problem into two simpler subproblems, one for finding the current into an AC ground and the other for finding the port impedance. A nodal voltage response is then given as the product of these two results, v _out  = i _sc  × DPI _out . Signal flow graph analysis is a technique for representing system algebra pictorially. The combination of these tools provides a unified approach to general circuit analysis. This chapter develops the DPI/SFG analysis methodology and demonstrates its application using a variety of circuits to show its versatility and power.