Automating NEC2 with Matlab® for antenna analysis and design

This work demonstrates the combination of NEC2, for electromagnetic computation, with Matlab, for composing input files and graphical display of the results. It presents Matlab-NEC2 automation as applied to adaptive array antenna synthesis and design. NEC2 (numerical electromagnetics code 2) is a popular program, with available source code, for numerical electromagnetic computations based on the moment method. NEC2 input is in the form of a text file with the data in 80-column format. The output is written to an ASCII text file, with headers followed by tables of values. Matlab is a very powerful matrix and math software package, with advanced file I/O and graphical display capabilities. Because the input file to NEC2 adheres to strict rules, the numerical data can be prepared in Matlab and then concatenated with the appropriate strings and written to a text file. Matlab can call the NEC2 executable from within one of its scripts (called m-files), and then read in the resulting NEC2 output file for further analysis. In essence, NEC2 becomes a solver driven by Matlab. Given an optimization strategy, Matlab can iterate the above-mentioned process, until convergence or another criterion is met.