A "how-to" guide to electromagnetic field-solvers. Many publications in this area are strictly theoretical, but this manual offers engineers advice on selecting the right tools for their RF (radio frequency) and high-speed digital circuit design work. The focus is on the strengths and weaknesses of the major commercial software packages with many tips and techniques on the use and evaluation of each. Real design case study material is included, along with a "what went wrong in the design process" discussion, when applicable.