Spline-Based Aspheric Dielectric Lens-Corrected Quad-Ridge Horn Antenna

In this letter, design and performance of a dual-polarized quad-ridge horn (QRH) operating over 3:1 bandwidth are discussed. In the proposed configuration, the QRH is loaded with a spline-based aspheric dielectric lens having a protrusion on the bottom, designed to achieve the required gain over the ±4° field of view (FOV). Exponential-shaped horn and ridges are employed to improve both the impedance bandwidth and the quality of radiation patterns. For dual polarization, an orthomode transducer with a turnstile junction as well as custom single and double-ridge waveguides is developed. To expand horn's use with nonwaveguide-based transmitters, a coaxial transition is also engineered. More than 24 dBi broadside and 21.5 dBi minimum gain within the FOV are achieved. Moreover, low sidelobe levels below −15 dB, cross-polarization discrimination greater than 30 dB, and symmetric patterns are demonstrated.