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Design of Four Elements UWB MIMO Antenna System with On Demand Band Notch Functionality

The design of a four elements ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna with on-demand band notch property is presented. The UWB MIMO an-tenna elements with on-demand band notch ability are analyzed for the 4 × 4 MIMO scenarios and proposed for UWB MIMO applications. The antenna is designed with a 1.6 mm thick FR4 substrate and the overall size of the antenna is 60 X 60 mm2. The radiating elements have the same shape and the stair steps are used for the wideband. L-shaped inverted stubs are located on the top of each radiating element and PIN diodes are inserted between these stubs to electronically control the notched band. Impedance matching is observed in all antenna elements from 3.1-10.6 GHz. Also, good isolation among all radiating elements is observed in the entire ultra-wideband. The correct length of the stub and its placement within the geometry of the UWB MIMO antenna control the effect on the rest of the radiating modes of the ultra-wideband structure.