The antenna has very compact size(9mm*10.5mm) and is placed over an FSS unit cell. A frequency-selective surface (FSS) is a thin, repetitive surface designed to reflect, transmit or absorb electromagnetic fields based on the frequency of the field. Integrating the antenna improves the gain and return loss of the antenna.The time domain performance of the antenna is to show the negligible distortion so that can make it perform better for medical imaging systems. Due to the better performance of the antenna the effect of the multilayer breast tissue is also investigated by calculating the fidelity factor across all the tissue layers. This biomedical application is a classical approach for non-destructive evaluation and belongs to Microwave tomography system. Now for better performance and to meet the requirements a Planar Monopole Antenna (PMA) is designed and optimized regarding to different parameters. A slot also been introduced to the design to find the better result.