Dual polarized reflectarray antenna to generate independent beams in Ku and Ka bands

Abstract

This contribution describes the design of a printed reflectarray antenna for operating at Ku and Ka frequency bands. The reflectarray has been designed to produce a focused beam at 11.95 and 20 GHz for both Horizontal and Vertical polarizations. The antenna is illuminated by a corrugated horn, modelled as a cos-q function with different q-factor values at 11.95 and 20 GHz. The periodic element is made of two stacked sets of dipoles, each of one comprising two orthogonal subsets of coplanar parallel dipoles, whose lengths are adjusted to focus the beam at each polarization and frequency band. The dimensions of all dipoles are calculated for a circular reflectarray of 33×33 elements (33-cm sided), using a MoM-SD based analysis routine and local periodicity approach. The simulated radiation patterns of the antenna show a gain of 30.7 dBi at 11.95 GHz and 34.2 dBi at 20 GHz, with side-lobe levels close to -21 dB.