A compact UWB MIMO antenna augmented with isolation improvement structures in situ with ground stubs and slots

An orthogonally oriented microstrip-fed bi-element ultra-wideband (UWB) diversity antenna possessing a super-wide bandwidth, high isolation, and band rejection attributes is proposed. The intended diversity antenna uses a 2nd-order Cayley fractal tree-shaped neutralization line among a pair of radiating square monopoles along with additional components like extended ground stubs, hybrid Koch fractal parasitic elements, and an L-shaped defected ground structure to attain high isolation of <−20 dB over 3.1–18 GHz. To nullify the intervention from the existent wireless local area network band, a hybrid Koch–Minkowski slot is carved out from the radiators. A minimal inter-element spacing of 8 mm is attained with the suggested layout measuring 28 mm (L) × 42 mm (W) in extent. The numerical as well as experimental investigations of vital diversity attributes like the envelope correlation coefficient, mean effective gain, total active reflection coefficient, and multiplexing efficiency depict high diversity actualization. The consistency amidst the simulation as well as the empirical results recommends the worthiness of the intended antenna for handy UWB and UWB multiple-input multiple-output systems.