Design and Analysis of Slot Loaded Microstrip Antenna for Breast Cancer Detection

Microwave breast imaging (MBI) promises a more accurate and safer modality for breast cancer detection to provide information about breast tissues that uses longer wavelength low power signals when compared to other conventional techniques like X-ray mammography. This paper includes the performance analysis of slot loaded microstrip patch antennas suitable for breast cancer detection. Four types of antennas structures: without any slits, with truncated corners, with L shaped slots and square shaped slits arranged serially are designed with the help of FR4(dielectric constant = 4.4) as the substrate which is simulated using CST software. The designed antenna has been compared with conventional ones and results shows the superiority of designed antenna in terms of S11parameter, gain, directivity, return loss. The gain of the designed antenna is far superior to that of conventional antennas. As such antennas are used extensively for medical applications the measure of specific absorption rate (SAR) becomes very critical. It has been observed in the different structures that insertion of slits, slots and truncations helps to vary the resonant frequency of the antenna and helps in achieving circular polarization which is needed for medical applications. Optimum performance is achieved using the designed antenna in terms of gain, VSWR, return loss and the radiation limits were obtained which falls within limit of 1.6 W/kg as recommended by FCC.