A low profile ultra-wide band (UWB) antenna array is presented for breast cancer detections using microwave imaging experiments. The sensor was designed to operate in the UWB band frequency scale of 3.1-10.6 GHz. Simulated and calculated result of the sensor are in good agreement. A dielectric with plastic material having low electrical properties was used to support the array elements experiments. The array configuration has a good mutual coupling between the adjacent antennas of below-20dB.