Circularly polarized stub-loaded annular ring patch antenna for 2×2 MIMO satellite application

Abstract

In this article, a stub loaded circularly polarized annular ring patch antenna which operates at 3–5 GHz band for 2×2 MIMO Satellite application is proposed. The evolution of antenna begins with a conventional annular ring patch antenna, addition of diagonal slots and integrated with λ/2 hair pin stub loaded annular ring patch to improve isolation and circular polarization. The antenna isolation is a critical parameter and important requirement of MIMO system. In satellite communications, circular polarization is used to improve the quality and reliability of the communication link between the satellite and the ground station. The antenna achieves circular polarization and mutual coupling through diagonal slots and stub-loaded design without any additional decoupling techniques. The overall size of the proposed MIMO antenna is 63 × 63 × 1.52 mm3 which is fabricated over Rogers RO3003 substrate. The proposed antenna design is simulated, fabricated, tested and analyzed for various parameters such as Reflection coefficient,Isolation Gain, radiation pattern, Axial ratio (AR), Envelope correlation coefficient (ECC), Diversity gain (DG), Channel capacity (CC) and total efficiency. The isolation of <−22 dB, gain of 7.1 dB, axial ratio<3 dB, diversity gain of 9.9 dB, ECC<0.002,CC of 11.23bps/Hz and efficiency>95% are obtained. The measured 10 dB impedance bandwidth of 270MHz and 3 dB AR bandwidth of 250MHz in the desired band are achieved. The simulated and measured antenna parameters are agreeable with each other. The results are found to be promising and having high potential in the 5G and Satellite MIMO.