Dual-resonance dielectric resonator-based MIMO antenna for Sub-6 GHz 5G and IoT applications

This communication introduces a Multiple Input Multiple Output (MIMO) antenna with dual resonance features, achieved through four dielectric resonators (DR). The design includes two larger (DR-1 and DR-2) and two smaller (DR-3 and DR-4) ceramic resonators (epsilon r = 9.8, tan delta = 0.002) positioned on a fan-shaped FR-4 substrate, fed with a circular ring-shaped aperture for generation of lower and upper-frequency bands respectively. The fan-shaped substrate, combined with an arc-shaped defective ground structure (DGS), is used to intensify the bandwidth of the lower band and improve the isolation between radiating DRs. The measured operating bands for larger-sized DRs are found to be 2.7 GHz-4.12 GHz (41.6 % fractional bandwidth (FBW)) and 2.7 GHz-4.2 GHz (43.47 % FBW), while for smaller-sized DRs are depicted to be 5.21 GHz-5.96 GHz (13.29 % FBW) and 5.21 GHz-6.12 GHz (15.93 % FBW) respectively. The measured isolations in the lower and upper bands at resonant frequencies 3.6 GHz and 5.5 GHz are determined to be better than -31.2 dB and -24.5 dB, respectively. The closeness between simulated and measured results makes the proposed antenna appropriate for Sub-6 GHz wireless applications like WLAN (5.25-5.95 GHz), WiMAX (3.3-3.8 GHz), 5G (n48, n77, n78 bands), and Wi-Fi (n46) enabled IoT.