This article presents a 2×1 CPW ultra wideband rectangular slot antenna array (UWB-RSAA) with modified circular slot shape to support high data rate for wireless communications applications. The proposed antenna array dimensions are 0.7λo×0.8λo×0.064λo at the resonant frequency 1.8 GHz and it is fabricated on a commercially available rogers RO4003 substrate (with εr = 3.5), which is fed by using coplanar waveguide (CPW). A graphene layer is added on the other side of the substrate to achieve frequency reconfigurable and improve the antenna array gain. The -10 dB impedance bandwidth of the RSAA extends from 1.7 GHz to 2.6 GHz, from 3.2 to 3.8 GHz and from 5.2 GHz to 7 GHz with peak gain of 7.5 dBi at 6.5 GHz at 0 Volt bias over the operating band with average gain of 4.5 dBi. When the graphene bias is increased to 20 Volt, the antenna bandwidth extend from 1 GHz to 4 GHz and from 5 to 7 GHz with array peak gain 14 dBi at 3.5 GHz and average gain 7.5 dBi. The proposed array achieved linear polarized behaviour over the operating bands to be suitable for short range UWB wireless communications and object detection. All simulation carried out using 3D high frequency structure simulator (HFSS) Ansys ver. 15.