Wideband Polarizer Using Dielectric Slabs with Periodic Rings for Satellite Communications

A wideband polarizer is presented using an array of dielectric slabs for K-band applications, such as satellite communications. To build the polarizer, a unit cell consisting of a single dielectric slab is first designed and simulated to study the polarization conversion performance. The incident linearly polarized plane wave is modelled by two orthogonal components transmitted from one port, and the phase shift between them is determined at the second port of the unit cell. Concentric conducting rings are added on both sides of the slab to improve impedance matching and thus widen the bandwidth. The proposed polarizer, formed of an array of dielectric slabs, is investigated using the CST software assuming an operation frequency of 20 GHz. The simulated results demonstrate that linear to circular polarization conversion is achieved over a fractional bandwidth of 43% extending from 15.8 to 24.5 GHz, while impedance matching is achieved across a 200% fractional bandwidth. Furthermore, the insertion loss associated with implementing the polarizer layer remains below 0.5 dB throughout the frequency range. The proposed polarizer is a suitable candidate for a linear polarized antenna array designed for K-band applications that use circular polarization.