Optimization of three-conductor microstrip line modal filter by heuristic search and genetic algorithms

The improvement of the protection against ultrashort pulse (USP) through the use of modal filters (MF) is considered. A review of researches dedicated to MFs based on multiconductor microstrip line (MSL) is made. A MF on the basis of a three-conductor MSL is investigated. Optimization of conductors separations in a MF is executed in two ways: heuristic search and genetic algorithm (GA). After optimization by using the GA we obtained an amplitude of USP at the output of MF that is 13% less than the one after heuristic search. It is proposed to use these methods successively.