A New CPW-Fed Diversity Antenna for MIMO 5G Smartphones

In this study, a new coplanar waveguide (CPW)-fed diversity antenna design is introduced for multiple-input-multiple-output (MIMO) smartphone applications. The diversity antenna is composed of a double-fed CPW-fed antenna with a pair of modified T-ring radiators. The antenna is designed to cover the frequency spectrum of commercial sub-6 GHz 5G communication (3.4-3.8 GHz and 3.8-4.2 GHz). It also provides high isolation, better than -16 dB, without an additional decoupling structure. It offers good potential to be deployed in future smartphones. Therefore, using four pairs of the proposed diversity antennas, characteristics and performance of an 8-port 5G smartphone antenna are investigated. Due to compact size and also placement of the elements, the presented CPW-fed smartphone antenna array design occupies a very small part of the smartphone board. Its operation band spans from 3.4 to 4.4 GHz. The simulated results agree well with measured results and the performance of the smartphone antenna design in the presence of user are given in the paper as well. The proposed MIMO design provides not only sufficing radiation coverage supporting different sides of the mainboard but also the polarization diversity