Design and Simulations of a Novel Ka-Band Isoflux Scanning Phased Array Antenna for GEO Satellites

In this letter, we propose a novel spaceborne isoflux scanning phased array (ISPA) antenna at Ka-band for geostationary Earth orbit satellite communications. The ISPA can adaptively compensate for space loss variation during beam scanning. An innovative method for achieving the isoflux scanning characteristics of ISPA by using shared subarrays with an isoflux beam as equivalent elements has been proposed and verified. Taking the space loss variation law derived from the satellite-ground model as the isoflux beam optimization goal, the challenge associated with subarray beam shaping is mitigated greatly by utilizing a shared subarray architecture with a sharing ratio of 4:1, enhancing the subarray's radiation aperture and element number substantially. The optimization results of the shared subarray by using a weighted alternating reverse projection method are verified in a full-wave simulation in ANSYS Electronics Desktop. Numerical results further demonstrate that the proposed ISPA can adaptively compensate for the inconsistency in satellite communication link variation during beam scanning and exhibits low sidelobes better than -20 dB while effectively suppressing grating lobes.