Enhancing Multi-Band MIMO Antenna Stability for Various Electronic Applications With Human-Body Interaction Consideration

This paper proposes a multi-band antenna suitable for LTE and 5G NR frequency bands. The multi-band antenna is designed on a 60-mm
$\times12.5$
-mm FR4 substrate without requiring passive components. The multi-band antenna uses a coupled-feed structure to reach the LTE900 frequency band, while the rest of the working frequency bands are implemented using a monopole antenna. multi-band antennas are implemented on electronic devices like smartphones, tablets, and laptops to form Multiple-Input Multiple-Output (MIMO) systems. Each multi-band antenna maintains consistency in measurement and simulation, with isolation below −10 dB, showcasing its robustness. The MIMO antenna system’s envelope cross-correlation remains below 0.5 across various devices, indicating stable performance. The above characteristics validate the multi-band antenna’s applicability to diverse-sized portable electronics. Furthermore, Specific Absorption Rate (SAR), assessing radiation’s impact on humans, is considered. Simulations of SAR for different MIMO antenna systems near the head, hand, or leg consistently meet safety standards, ensuring that MIMO antenna systems pose no radiation threat to human health.