Large bandwidth of Polydimethylsiloxane (PDMS) magnetite graphene sensor is realized by addition of ferrite element. (Fe3O4). 35% of ferrite portion has been chosen to be combine with 65% of PDMS to form low permittivity (2.85) and low loss tangent (0.067) of substrate for the sensor. The sensor consists of graphene as the 4 × 1 array radiating patch, quarter-wavelength transmission line, parasitic element, partial ground and reflector while PDMS Ferrite as the substrate. The sensor recorded ultra-wide band radiation (2.5 GHz-11.2 GHz) with high energy (2.5dB-11.7dB) in microwave frequency ranges. As compared with conventional substrate (Taconic), the new substrate (PDMS-Fe3O4) recorded 25% of bandwidth enhancement as much as 2 GHz. Wide bandwidth and high energy sensor are essential in human microwave detection system for penetrating the multilayer structures by enhancing the focus of the electromagnetic energy into the desired structure. Maximum power of 11.7 dB and small dimensions of 90 mm × 45 mm made the UWB sensor suitable enough to be applied and integrated in microwave detection.