Ridged Apertures for LEO Direct Radiating Arrays in Ka-Band

This paper presents an extensive performance analysis of open-ended waveguide elements for direct radiating arrays with a high scan angle (±50◦/60◦). The evaluated designs are based on square and hexagonal apertures loaded with ridges. Both square and triangular lattices are considered in the framework of Ka-band downlink design requirements for future LEO mega-constellations. The parameter space defined by the monomodal condition has been explored to find an optimum value for each structure. The analyses carried out with both infinite and finite full-wave models in terms of active reflection coefficient, scan loss and cross-polar discrimination are in good agreement.