Monostatic Radar-Based Microwave Imaging of Breast Tumor Using an Ultra-wideband Dielectric Resonator Antenna (DRA) with a Sierpinski Fractal Defected Ground Structure

摘要

A rectangular DRA with a Sierpinski fractal defected ground structure has been simulated and experimentally tested for UWB operation to be used in the detection of breast tumor using monostatic radar-based microwave imaging (MRMI). The proposed fractal DRA is designed to cover UWB characteristics (5.6-14.2 GHz) and high peak gain (5.8 dB). Then it is used as a sensor for extracting S-parameters from the breast phantom for tumor detection. In this regard, the fractal DRA is positioned in front of phantom, revolved around it (10 degrees) in elevation and azimuthal plane to collect backscattered signals (with/without tumor). For validation, an artificial phantom of breast consisting of three layers, gelatin (skin), petroleum jelly (fat) and wheat flour (tumor), with electrical properties same as that of human breast is prepared and the S-parameters are recorded at different intervals. The captured reflection parameters processed in different imaging algorithms are: delay and sum and coherent factor (DAS-CF) and delay multiply and sum and coherent factor (DMAS-CF) to reconstruct 2D images of the breast tumor using MATLAB. The simulated specific absorption rate of the proposed DRA on the breast phantom at the resonant frequencies of 6.1 and 13.9 GHz was observed to be 1.02 and 1.13 W/Kg, respectively, which is safe limit for human exposure.