Compact Size MIMO Amer Fractal Slot Antenna for 3G, LTE (4G), WLAN, WiMAX, ISM and 5G Communications

In this study, an Amer fractal slot antenna is proposed as a multiple input, multiple output (MIMO) antenna with four ports. The antenna is excited by CPW (coplanar waveguide) to control the leakage of electromagnetic energy, which leads to a high match between the antenna and input impedance, thus achieving dual operating bands of 1.5-19.2 GHz and 25-37.2 GHz for port 1, dual operating bands of 1.4-19 GHz and 20-35.5 GHz for port 2, a wide operating band of 1.4-29 GHz for port 3, and dual operating bands of 1.6-21 GHz and 22-37 GHz for port 4. Therefore, the proposed antenna meets all the market needs of wireless communication technologies such as 3G, Long Term Evolution (LTE, 2.6 GHz /3.5 GHz), Wireless Local Area Network (WLAN, 2.4 GHz/5 GHz), Worldwide Interoperability for Microwave Access (WiMAX, 2.5 GHz/3.5 GHz/5 GHz), Industrial, Scientific and Medical (ISM, 2.4 GHz/ 5 GHz), and 5G (5-6 GHz and 27-28 GHz). The proposed antenna can be used as dual opposite ports for the frequency range 1.5-15 GHz and as four-element MIMO arrays for frequencies of 15-30 GHz. The MIMO fractal antenna has circular polarization characteristics with axial ratio bandwidths (ARBWs) of 4.7-5.8 GHz for port 1, 2.5-2.6 GHz and 5.4-6.5 GHz for the port 2, 4-5.9 GHz for port 3, and 5.5-10 GHz for port 4. Due to its compact size (33 mm × 33 mm × 0.8 mm), low profile, and acceptable values of gain and efficiency, the proposed antenna is suitable for many portable wireless communication devices.