Parameter correlation of impulse shapes using twoport synthesis
Abstract
Standard techniques for testing devices and systems for their response to lightning, switching transients, and electromagnetic pulse (EMP) disturbances often call for impulse shapes characterized by double exponential functions. Unfortunately, the time constants and impulse parameters such as rise time, pulse, duration, time to peak, and others are not directly related. The problem in generating test impulses is that the required standard impulses are sometimes defined by parameters and nomenclature lacking direct correlation to the desired time constants needed to derive component values for prototype impulse generator circuits. This paper derives equations for determining the time constants of the double exponential impulse from the commonly used parameters for several standard test impulses. It then proceeds to synthesize a resistorcapacitor (RC) prototype circuit that will produce the desired impulse. The prototype network is realized through a computeraided design (CAD) procedure using Cauer's RC ladder twoport synthesis method. Descriptions of prototype circuits and test data comparing the theoretical and experimental impulse shapes are also included. The results are a simplified method for determining time constants of a double exponential function from given impulse parameters and a method for deriving the component values for prototype circuits.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 May 1991
 Bibcode:
 1991STIN...9122505G
 Keywords:

 Exponential Functions;
 Impulse Generators;
 Network Synthesis;
 Performance Tests;
 Rc Circuits;
 Surges;
 Switching Circuits;
 Transient Response;
 Circuits;
 Computer Aided Design;
 Electromagnetic Pulses;
 Lightning;
 Electronics and Electrical Engineering