A Novel Logarithmic-Spiral-Shaped 3-D-Printed Dielectric Polarizer for Dual-Circularly Polarized Conical-Beam Radiation Patterns in the Ka-Band

In this contribution, the design of a novel logarithmic-spiral-shaped (LSS) anisotropic dielectric polarizer is presented for millimeter-wave applications within the Ka-band (28-30 GHz). The proposed antenna is composed of a conical horn fed by a waveguide dual-mode converter (DMC), where the TE01 and TM01 modes are independently excited to generate linearly azimuthal polarized and linearly radial polarized conical beam radiation patterns, respectively. The horn antenna is loaded with the novel LSS dielectric polarizer, which converts the linearly azimuthal polarized wave generated by the excitation of the TE01 mode into a right-handed circularly polarized (RHCP) wave and the linearly radial polarized wave generated by the excitation of the TM01 mode into a left-handed circularly polarized (LHCP) wave. In order to experimentally validate the proposed design, both the DMC along with the conical horn antenna and the novel LSS dielectric polarizer are manufactured by means of distinct 3-D printing techniques. An excellent agreement between simulations and measurements is achieved.