All-Metal Connected-Element Arrays for LEO Orbits in Ka-Band

This paper presents a compact six-ridged hexagonal waveguide aperture with integrated grooves, developed for Kaband transmit array applications within the framework of next-generation non-terrestrial networks. The proposed design combines sixfold geometric symmetry with a continuous groove structure to enhance polarization stability, reduce inter-element coupling, and maintain broadband impedance matching over wide scanning angles. The aperture operates efficiently across the 17.7-20.2 GHz band, achieving reflection and coupling levels below −10 dB, scan loss under 3 dB up to 50°, and crosspolarization discrimination above 15 dB up to 60°. A sevenelement cluster implementation validates the element's robustness and wide-angle performance. Results confirm the suitability of the proposed aperture for compact, high-efficiency Ka-band phased arrays in satellite communication payloads.