High-isolation Coradiator-Based UWB MIMO Antenna for On-Body IoT Applications

In this paper, a compact ultra-wideband (UWB) dual-port MIMO dielectric resonator antenna (DRA) with defected ground plane is proposed for on-body wireless body area network (WBAN) applications. The antenna employs a U-shaped dielectric resonator, two microstrip feeds, and parasitic strips to achieve wide impedance bandwidth and enhanced port isolation. Results reveal that wider and longer slots significantly improve impedance matching and inter-port isolation, while increasing slot depth in the dielectric enhances bandwidth and reduces coupling by suppressing surface currents. The fabricated prototype was experimentally validated on both rectangular and cylindrical tissue phantoms, as well as on animal tissue, demonstrating good agreement with simulations. The proposed antenna covers the UWB frequency range of 3.1-10.6 GHz with return loss below -10 dB and mutual coupling below -20 dB across the band. Furthermore, radiation analysis confirms broadside coverage with opposite phases for dual ports, ensuring reduced fading and improved channel capacity. The results confirm that the proposed antenna is robust for wearable and biomedical IoT devices requiring high data rates, low power consumption, and reliable UWB MIMO communication.