Low-profile diffraction antenna array with wide-angle scanning for perspective satellite communication systems

Satellite communication systems (SCS) play a pivotal role in delivering telecommunication services to remote and underserved areas, where terrestrial infrastructure is lacking. With the growth of non-geostationary satellite constellations, modern SCS demand antennas that combine high efficiency, compact size, and broad scanning angles to ensure seamless connectivity regardless of geographical location. The study addresses the limitations of traditional satellite terminal antennas, such as high costs and restricted scanning sectors in electronically steered arrays or slow response times in mechanically scanned systems. This work introduces a novel scanning diffraction antenna array based on a Variable Inclination Continuous Transverse Stub (VICTS) design. The proposed antenna achieves a scanning sector of ±65° in elevation with a low-profile structure of 50 mm, making it suitable for mobile and stationary satellite terminals. Key results include the development of a broadband microstrip radiating element, operational between 10.7 and 14.5 GHz, coupled with a gap-waveguide phase shifter providing a full 360° phase delay. Electromagnetic modeling demonstrated the array's scanning capability of ±60° with an efficiency of approximately 50% across its operating frequency range. The use of a gap-waveguide phase shifter eliminates frequency-dependent scanning, a challenge in conventional designs. The VICTS antenna comprises two rotating aluminum disks, with the upper disk hosting linear slot radiators and the lower disk forming the power distribution network. The unique structural design enhances uniform amplitude distribution while minimizing fabrication complexity and sensitivity to assembly tolerances. Measurements of S-parameters confirm low reflection losses (below –20 dB) and minimal signal leakage, ensuring robust performance. The array's suitability for next-generation SCS is evident from its low-cost implementation, high-speed scanning potential, and adaptability for vehicular applications. While its frequency-scanning behavior and linear polarization require additional considerations, such as external polarizers, the concept demonstrates significant promise for ground terminals in non-geostationary satellite networks. This work contributes to the advancement of accessible, high-performance satellite communication technologies.