In this book, the first part present the simulations and experimental results of a series of patch antennas in wide band. The conception of these patch antennas are realized by software HFSS "Ansoft-High Frequency Structure Simulator" and ADS "Advanced Design System", themselves based essentially on the variation of the shape of the antenna, conductive material, the nature and the thickness of the substratum to have a structure which resounds in the frequencies used for precise applications. The simulations and experimental results are compared to those published in the bibliography. In the second part, we present the simulations results of the Broadband and dual band microstrip antenna. This are serves to join the telecommunication services by using a single antenna. Antennas broadband and dual band were obtained by using, respectively, the technique of pile of patches and hybrid antenna. The broadband antenna is established by two patches stacked, fed by aperture coupling and the dual band antenna is a hybrid antenna consisted of an annular microstrip antenna and a wave guide. The effects of the constitutional parameters of antennas were studied.