8-Loop Antenna Array in the 5 Inches Size Smartphone for 5G Communication the 3.4 GHz-3.6 GHz Band MIMO Operation

Abstract

This dissertation proposes a design and architecture of eight loop antennas proposed in a limited space, a 3.5 GHz band (3.4 GHz-3.6 GHz) for 5G communication [1], and a multi-input multiple-output (MIMO) smartphone. In the limited space of a simulated 5 inches screen smartphone, taking into account of the cell phone battery and LCD screens and electronic components may affect the antenna, the surrounding environment is defined as copper metal ground. The overall size of the smartphone is 70 × 145 × 8 mm3 and is designed for an antenna range of 10 × 55 × 5 mm3 and 10 × 100 × 5 mm3, the single designed loop antenna volume is 14.2 × 9.4 mm2 suitable for as the 5G smart phone embedded antenna. Three and five loop antennas are placed on the top of the FR4 board in a stacking manner of two sides. For these 8 proposed loop antenna with enough bandwidth of the band 3.4-3.6 GHz [2], return losses S11 to S88 Spec. < −6 dB, mutually acceptable isolation approximately 15 dB, the correlation value ECC (Envelope Correlation Coefficient) of any two antennas less than 0.2 [3], the single loop antenna efficiency is about 40% and the overall antenna gain is 2 dBi. The experimental results are presented and discussed.