What is MIMO (Multiple-Input Multiple-Output) Antenna

A novel compact ultra-wideband (UWB) multiple-input multiple-output (MIMO) slot antenna with band notch characteristics is presented for portable wireless UWB applications. The antenna comprises of co-planar waveguide feed (CPW) and two radiating monopoles oriented in orthogonal orientation for providing orthogonal radiation patterns. A Minkowski fractal parasitic stub along with a Minkowski fractal grounded stub has been placed at 45° between the monopoles to reduce the coupling between them, which in turn establishes high isolation between the radiators. An excellent band notch characteristic is obtained at 5.5 GHz by etching a modified E-shaped compact slot on the radiators. Results show that the designed antenna meets -10 dB impedance bandwidth and -17 dB isolation throughout the entire operating band (3.1 -12 GHz). Novelty of this design lies in improving isolation using fractal which occupies less space in compared to other isolation mechanisms in MIMO structures. The simulated and measured results depict that the proposed antenna is convenient for MIMO diversity systems.