In two previous chapters, the analysis and simulation of some microstrip test circuits were performed. Here, in order to validate the theoretical procedures, the results of its physical characterization using a commercial network analyzer are presented. The first measurement was done over a simple 25-Ω microstrip transmission line. The line was constructed using a substrate of polythetrafluoroetilene (Teflon) with a dielectric constant of 10.5 (DUROID® 6010, ε r = 10.5). As previously mentioned, the synthesis was carried out with the method of moments (MoM), using the program presented in Chapter 2. The obtained dimensions were H = 0.1882 cm and L = 3.7 cm.