A Miniaturized, Dual-Port, Multiband MIMO with CSRR DGS for Internet of Things Using WLAN Communication Standards

Abstract

A compact, dual-port, triband MIMO antenna is designed and tested for three sub-6 GHz WLAN bands for IoT applications. The size and performance of the antenna make it versatile for the emerging IoT applications communicating using the 2.4 GHz, 5.2 GHz, and 5.8 GHz WLAN frequencies. The single radiating element of antenna geometry includes a pair of modified and optimized rectangular patches. A complimentary split ring resonator (CSRR) structure is incorporated in the ground plane as a defect (defected ground structure) to attain the third operational band. The orientation of the elements, orthogonally arranged, along with DGS, enhances the isolation between the radiating elements keeping it below 18 dB throughout the three operating frequency bands. The size of the final antenna is as small as $0.32{\lambda }_0\times 0.32{\lambda }_0$  mm2 build on commercially available and cheap FR4 substrate of thickness 1.5748 mm. A peak gain of 7.17 dBi is attained for the proposed MIMO system. This MIMO antenna also satisfies the diversity parameter requirements including $\text{DG}>9.8$ , $\text{ECC}<0.5$ , $\text{TARC}<-10$  dB, and $\text{CCL}<0.5$ bits/s/Hz. This makes the proposed antenna a good candidate for IoT applications employing WLAN frequencies.