Bandwidth and Radiation Pattern Enhancement of Monopole Antenna Using Shorting Pin for Microwave Breast Imaging Application

Microwave breast imaging is a non-ionizing and non-invasive technique for detecting and diagnosing breast cancer. An antenna is necessary for microwave breast imaging to provide the required resolution, penetration, safety, and compatibility with microwave signals, allowing for the precise and safe detection of breast abnormalities. In this study, a method for enhancing the monopole antenna bandwidth and radiation pattern was implemented by shorting the pins of the radiator and ground plane. Based on the simulation results, shorting the pins in the monopole antenna increased the bandwidth by 1.04 GHz, increased the peak gain by 0.66 dBi, and increased the front-to-back ratio (FBR) at 8 GHz by 3.97 dBi. In tumor detection simulation under breast phantom conditions with tumors, the S11 frequency resonant frequency shifted from 4.64 GHz to 4.70 GHz in non-tumor conditions. The changes in the resonant frequency observed across the three conditions indicate that the antenna can identify the phantom state of the breast, with or without a tumors.