I. Introduction
The intensive development of wireless communication systems creates new requirements for antennas as a part of it. Wireless data transmission within the latest telecommunications standards put high demands on the efficiency of antennas. The main latest trends in antennas are broad operational bandwidth, high directional characteristics, and the ability to control the beam direction. Many of these requirements can be met by using reconfigurable transmitarray antenna [1]. However, this can also be achieved using lens antennas, which typically consist of a lens body and a feed antenna. This approach would be cost effective. There are various types of lens antennas, for example, homogeneous dielectric antennas [2] or antennas with a gradient refractive index (GRIN) [3].