Two-Element UWB Antenna with Multiple Open Slots in Fountain-Shaped Ground for Wearable and Biomedical Applications

This article proposed a compact dual-port ultra-wideband (UWB) antenna with multiple-input multiple-output (MIMO) technology for wireless mobile communication, wearable, and breast cancer detection applications. MIMO antenna elements are based on rectangular-shaped patches, which are inspired by half-cutting technology to provide UWB response and compact size of the antenna. A fountain-shaped decoupling structure with multiple open slots in the connected ground layer is utilized to minimize the surface current between two rectangular-shaped radiators. The length of open-ended slots is considered ≈ λ 0 /4 (λ 0 is the lowest operating frequency) which elongates the current path and helps to reduce the current flow from port-1 to port-2. The decoupling structure contributes to the isolation greater than 20 dB in the UWB frequencies that operates from 2.9 to 10.4 GHz without affecting the gain and radiation efficiency. The dimension of the MIMO antenna is 25 mm X 35 mm X 1.6 mm, with a peak realized gain of 5 dBi. The edge-to-edge distance between the radiating elements is 0.183λ 0 which is less than conventional distance (0.5λ 0 ). The two-port MIMO antenna is compact in size, has a simple decoupling structure, is designed on easily available material, and can be a good choice for metrological instruments in wearable, portable, IoT, and 5G applications. Diversity characteristics of the MIMO antenna are estimated such as ECC