Wide-Beam Metallic Bezel Antenna for Direct Satellite-to-Handset Communications

This article presents a compact wide-beam metallic bezel antenna for low Earth orbit (LEO) mobile terminal satellite communications. Inspired by the tri-current model with isotropic radiation, the proposed antenna is designed using a tri-folded dipole around the main board with two capacitive loadings, which optimize the capacitance-inductance relationship between the tri-folded dipole and the ground. Therefore, the ground functions as a reflector rather a director to achieve the wide-beam coverage. Furthermore, the capacitive loadings also suppress the unwanted higher order modes which may degrade the beam coverage. To validate the design, a prototype antenna was fabricated and tested. The experimental results indicate a −6-dB impedance bandwidth of 240 MHz (12.5%), and a 3-dB beamwidth of 181°/142° within a clearance of 0.5 mm at the center frequency of 1.9 GHz. This antenna offers advantages of small clearance, wide beam coverage, and compatibility with mobile phone bezel, making it a feasible solution for the LEO direct satellite-to-handset communications (DSHCs).