Free and Open Source Software for Electromagnetic Engineering: a Review

Numerical simulation applied to electromagnetic scattering problems represents a very broad and multifaceted field. Historically, its bases derive from the initial attempts to find numerical solutions for describing electromagnetic propagation phenomena in complex and realistic scenarios, where analytical calculations were inapplicable. Over the past years, with the enormous increase in the available computer power, simulation software for electromagnetic analysis and design has become more and more popular. In this fast-growing background, the use and the development of numerical software for electromagnetic simulation follow two main directions: a) In the industrial world, the standard approach is to employ commercial software suites, because of their easy integration in the design workflow, as well as their extended support and documentation. However, they present high costs, both at the time of purchase and for the maintenance of licenses and upgrades. Furthermore, being closed source, commercial code cannot be easily extended by the user or modified and studied for research purposes. b) In the academic world, it is very frequent to develop in-house simulation software from scratch, or alternatively to modify existing software packages in order to experiment new models and algorithms. In other words, the development of electromagnetic simulation software is still a wide research field itself, as witnessed by many recent papers on this topic. However, in both situations, the knowledge of the existing open-source possibilities is often scarce. In both academic and industrial frameworks, especially when the available budget is rather low, it is more common to find illegal versions of commercial software suites rather than move to their open-source counterparts. Of course, this creates an important ethic problem, which is also accompanied by a series of potential security concerns. Moreover, it is very rare that more than one academic institution work together for the practical development of open-source simulation packages, and it is more than rare that both universities and companies work together on that. The only exception is represented by several public-funding research projects at national or international levels. However, when such projects come to an end, these joint efforts encounter significant difficulties. In the light of the last considerations, the availability of free/libre and open source software (FLOSS) for electromagnetic design would be of great value not only for the scientific communities, but also for small companies, struggling to face the costs related to commercial products. Furthermore, open source codes could be proposed as an interesting alternative to commercial codes in courses about electromagnetic theory and design. Cultural motivations also exist: in the research and scientific community there is nowadays an increasing demand of open data, results, algorithms, and codes, and open source is the natural choice when such ethical concerns about science diffusion and reproducibility are faced