36–90 GHz Modular Lens-Corrected Dual-Polarized Horn With Cavity

Additive manufacturing enabled wideband, dual-polarized antenna operating from 36 to 90 GHz is proposed. This highly modular configuration is comprised of a quad-ridge horn (QRH) antenna with a monolithically integrated waveguide orthomode transducer, a dielectric lens, and an absorber-lined cavity for pattern control. Exponential tapering of the horn, cavity, and ridges is used to enhance the impedance bandwidth and radiation patterns. The 3-D printed plano-convex dielectric lens is added to increase aperture efficiency to over 70% across the band. Moreover, the inclusion of a cavity module with a current sheet absorber is shown to significantly enhance the sidelobe level (SLL) and beam efficiency (BE), while enabling flush-mounting implementation. Various additive manufacturing techniques are deployed to enable a prototype with measured VSWR <2.5:1 from 36 to 44 GHz and <2:1 for the rest of the band in both channels. Broadside gain exceeding 26 dBi, radiation and BEs above 75% and 88%, respectively, is obtained. The SLLs
$\lt -25$
dB and symmetric patterns are also demonstrated. Good agreement between simulation and measurements validates the robustness of the proposed modular antenna system.