A 24 GHz Dual-Polarized and Robust Dielectric Rod Antenna

This paper presents a robust and easy manufacturable dual linear-polarized dielectric waveguide antenna (DRA) for the 24 GHz industrial, scientific, and medical band. Dual-polarized operation is achieved by utilizing a square metal waveguide and a conical horn for exciting the surface wave on a tapered dielectric rod. In order to couple a signal into the square waveguide, an innovative dual-polarized, aperture-coupled microstrip-to-waveguide transition is shown. Additionally, two kinds of radomes, i.e., a foam radome and a half-wave wall monolithic radome are presented to protect the DRA. The antenna achieves a 10 dB bandwidth of 1.7 GHz and a gain of 11.5 dB including losses caused by the transitions and connectors. The sidelobe level and the cross-polarization level are lower than -25 and -26 dB, respectively. Designs and measurement results of all components are described in detail in this paper.