Different contributions made to the development of Transmitarrays (TA) for Far-Filed applications are presented in this contribution. Firstly, two unit cells working at the frequency of 10GHz are presented, one based on four patches couple by a slot or a symmetric cross, is introduced, and the other, a 2-bit unit cell based on an ultra-thin structure made by 2 coupled patches. Then, an array-based model used to analyze a system formed by a TA and a planar lens in a time-efficient manner without using a full-wave method is introduced. Thus, both features are used to design and analyze the different prototypes reviewed in this contribution. That is, an ultra-thin planar lens based on the 2-bit unit cell and a dual-polarized TA that has been designed in order to be used in polarized agile antenna. Thus, by rotating the feed of the system, a linear polarized antenna, it is possible to obtain any kind of polarization, form linear to circular. Finally, a TA for a multibeam application fed with a network of quasi-yagi antennas has been designed.