Eight element dual-band MIMO array antenna for modern fifth generation mobile phones

Abstract

In this paper, an eight-element multiple-input multiple-output (MIMO) antenna with dual-band response is designed for fifth-generation (5G) mobile devices. The proposed MIMO systems’ radiators are placed in the inner side frame of the mobile phone board, which has a size of 150 × 7 mm2, each spanning an area of 21.5 × 5.5 mm2. All eight antenna elements are symmetrical to each other and are fed with a 50? feeding line. The proposed MIMO antenna covers two distinct 5G frequency bands, i.e., 3.5 and 5.3 GHz, and offers ?6 dB impedance bandwidth in a frequency range of 3.4–3.65 and 4.8–5.8 GHz. It is worth mentioning that an isolation of more than 18 dB is achieved over the bands of interest without the use of a decoupling network. Similarly, the proposed MIMO antenna achieved an efficiency of more than 60% across the bands, an envelope correlation coefficient (ECC) below 0.04, antenna gain better than 5 dBi, a mean effective gain (MEG) between any two radiating elements found to be better than 3 dB, and a channel capacity (CC) above 38.5 bps/Hz, which is three times better compared to a 2 × 2 MIMO antenna system. Upon fabrication and testing of the proposed antenna, it was noted that the measured results are in good agreement with the simulated data. Furthermore, the MIMO antenna response was simulated in the presence of a human user and shows how the user phantom affects the radiation characteristics of the MIMO antenna. These performance parameters showed promising results, making the proposed design a better option to be deployed in modern-day 5G communication application scenarios, specifically cell phones.