Optimization of modal filter design for ultrashort pulses propagation from two directions

Authors: Gordeeva V. O., Belousov A. O.

Annotation: The article is the first to consider the optimization of a strip modal filter (MF) using the criterion of minimizing the maxi-mum amplitude of ultrashort pulses (USPs) in case of two di-rection propagation. The authors have implemented this by using the animated dynamic visualization submodule «DynaVis», that allows to estimate the change in the signal shape alongside the specific MF conductor. The optimization was performed using a genetic algorithm with tournament elimination at the selection stage. For the first time, during optimization, we spe-cified a number of optimized parameters not by ranges, but by a discrete set of values at the stage of generating a new genera-tion. The optimization process entails high computational time costs because the algorithm calculates voltage values at multiple nodes corresponding to the number of subsections (50 in this case) into which the MF is divided during optimization. As a result, the optimization achieved the lowest maximum voltage level of 159.8 mV in the central section of the MF (node 25 out of 50) under the excitation of trapezoidal USPs with an EMF of 1000 mV from sources E1 and E2, and the 717 mV at node 22 under the excitation of USPs corresponding to IRA II with an EMF of 5647 mV (E1) and SINUS-160 with an EMF of 2575 mV (E2) generators. The obtained results were evaluated according to several criteria.

Keywords: genetic algorithm, modal filter, ultrashort pulse, optimization, electromagnetic compatibility