Folded transmitarray antenna for SatCom receivers at K-band

Overview & Synopsis

This paper presents the design of a folded, reconfigurable transmitarray antenna operating at K-band. The chosen unit-cell is a 2-bit structure composed of linearly polarized patches and four p-i-n diodes. The antenna achieves switchable circular polarization by employing a random sequential rotation scheme of vertically and horizontally polarized patches in transmission. To reduce the focal distance by a factor of approximately 3 compared to standard illumination, a broadband reflecting polarization converter is integrated into the system. A 24×24-element transmitarray was designed and analyzed using an in-house simulation tool. The antenna achieves a peak gain of 24.5 dBiC, with scan losses of less than 5 dB across a scan range of ±60 degrees. Finally, the accuracy of the design methodology was validated through comparisons with full-wave simulations, based on a simplified fixed-beam folded transmitarray design.