FSS-Inspired Transmitarray for Two-Dimensional Antenna Beamsteering

A novel two-dimensional (2-D) beamsteering transmitarray inspired on frequency selective surfaces is proposed in this paper. Individual phase range is applied to each transmitarray element and thus enabling the steering of the main lobe of an original antenna pattern in both elevation and azimuth planes (2-D-beamsteering). This has been demonstrated on a 5 x 5 unit-cell stacked structure, loaded with surface mount capacitors, coupled to the aperture of a standard gain horn antenna. Additionally, a complete parametric study based on electromagnetic (EM) simulations using CST Microwave Studio is presented to evaluate and characterize unit-cell parameters and the behavior of the array with various numbers of stacked layers and separation distances. Antenna beamsteering with ranges up to Az = 25 degrees and El = 25 degrees are achieved by means of EM simulations and validated against experimental results performed on a physical prototype at 5.3 GHz. The comparisons yield positive results and clearly demonstrate the potential and limitations of using such structures for beamsteering purposes.