A highly compact two-port UWB MIMO antenna with enhanced performance and low mutual coupling for IoT applications

Ultra-wideband (UWB) technology has emerged as a promising solution for applications in indoor positioning systems, medical instrumentation, and Internet of Things (IoT) environments, owing to its extremely low power consumption, good temporal resolution, and intrinsic resilience to multipath propagation and signal attenuation. In this work, a compact two-port, multiple-input multiple-output (MIMO) antenna system with an extensive band response and low mutual coupling characteristic for ultra-wideband (UWB) application is proposed. The design simplicity, unique decoupling structure, high performance, and low mutual coupling throughout the operating band make the proposed design novel. The design has a size of 35 × 46 mm 2 with 0.17 × 0.23 λ 2 electrical length, making it highly compact for the desired wireless applications. The design consists of a partial ground, two radiating elements, and a decoupling structure. Multiple slots in the radiating elements and partial ground with rounded corners have helped to generate a very wide band response with good impedance matching, which covers UWB and additional bands for numerous wireless applications. The simulated and fabricated prototype has achieved 172% (1.5–20 GHz) fractional bandwidth. The decoupling structure has highly improved port isolation throughout the operating band, with a minimum of 25 dB isolation. The proposed MIMO design has demonstrated good performance in terms of simulated and measured gain throughout the operating band, with a peak gain of 4.69 dBi at 13 GHz. The proposed design demonstrates stable MIMO performance, as evidenced by low envelope correlation coefficient (ECC), high diversity gain (DG), and acceptable channel capacity loss (CCL). Given its ultra-wide operational bandwidth and robust MIMO characteristics, the antenna system is well-suited for a broad range of medical and advanced wireless communication applications.