The millimeter wave and sub-THz region, which correspond to the region that contains the 30GHz-1THz zone of the frequency band, has wide types of application, that covers from space purposes, such as astronomy, to earth applications, weather study, and automotive industries, among other innovative uses. In recent years, this frequency range become more interesting for its use, related to obtaining more advantages from applications previously done at lower frequencies and the introduction of novel applications. However, the desire to use high frequencies implies the addition of new challenges to face, not only in the theory used for the design of new structures but in the measuring and the study of the prototypes to build.