Design and analysis of two elements reconfigurable ultra-wideband multi input multi output (UWB-MIMO) antenna for wireless applications

A new compact frequency tuning antenna with a single element and two polarized elements for Ultra-Wideband Multi Input Multi Output (UWB-MIMO) wireless applications is designed and analyzed using the CST package. The proposed antenna supports four PIN diodes for frequency tuning and controls the frequency band from UWB band to narrowband through their ON/OFF states. The proposed 2-elements structure is designed using FR4 substrate with overall dimensions of (30x60x1.6) mm3, the relative permittivity of 4.3, microstrip line feed with 50 Ω, and the antenna comprises patch element with an elliptical-shaped of radii of (10, 8) mm, two stubs with equal dimensions of (10x4) mm2 connected to the microstrip line feed by PIN diodes and half elliptical GND plane with radii of (15, 7) mm. The proposed antenna operates with three frequencies with bands under (S11 ≤ -10 dB) from (3-9.65) GHz, (6.13-7.21) GHz, and (5.45-7.6) GHz according to the PIN diodes states. These bands can be used to cover UWB, Satellite, and WiMAX applications. The maximum gain is 4.2 dB and the lowest return loss is -46 dB at 6.68 GHz. The performances behind this design are less than 0.022, around 10, less than -20 dB for the Envelope-Correlation-Coefficient (ECC), Diversity-Gain (DV), and Isolation respectively.