This paper proposes high gain ultra-wide band (UWB) reflector array antenna for human brain tumor detection using specific absorption rate (SAR) technique in microwave detection system. Introduction of copper reflector with ideal distance contribute in increasing the proposed antenna gain. High gain antenna is essential in human microwave detection system for penetrating the multilayer structures by enhancing the focus of the electromagnetic energy into the desired structure. The antenna with reflector recorded wider bandwidth; 1.6 GHz-10.8 GHz associated with higher gain ranged from 3.2 dB until 14.1 dB compared with antenna without reflector operated from 2.2 GHz to 10.8 GHz with lower gain ranges of 2.1 dB to 10.2 dB. The antenna is successfully detecting human brain tumor based on SAR technique. Amount of energy or gain produced by the antenna which being absorbed by the human brain indicated the present of tumor inside. Human brain with tumor absorbed more energy and recorded higher SAR value compared to human brain without tumor. In this paper, human head phantom associated with tumor recorded SAR value of 2.53 W/kg and 2.51 W/kg for simulated and measured respectively meanwhile head phantom without tumor stated SAR value of 1.06 W/kg for simulated and 1.05 W/kg for measured. The biggest different in SAR value according to area precisely determine the location of the tumor in the brain which in this case position 5 (tumor location) resulted biggest SAR different value of 1.47 W/Kg for simulated and 1.46 W/Kg for measured.
