Compact eight MIMO antennas for 5G smartphones and their MIMO capacity verification

The handset or smartphone antenna has evolved from the external antenna before the year 2000 to the internal antenna and casing-integrated antenna for 2G/3G/4G communications till now. For the fifth-generation (5G) communications, it is expected that the Massive MIMO system is very promising for applications and a large number of MIMO antennas will be attractive to be deployed in the smartphone to effectively increase the channel capacity. In this paper, promising compact eight MIMO antennas in the smartphone are presented. The MIMO antennas are operated in the 3.5-GHz band (3400~3600 MHz), which has been recently identified in WRC-15 for global mobile broadband services in the future. The achievable MIMO channel capacities for the proposed compact eight MIMO antennas are calculated and verified by MIMO OTA (over-the-air) testing in the open space. Results are presented and discussed.