A compact modified wideband antenna with CBCPW, stubline and notch-staircase for breast cancer microwave imaging application

Abstract Controlling desired frequency without affecting physical size of wideband microstrip antenna is a challenging issue especially for breast cancer microwave imaging application. This paper presents a solution for improving the lower frequency operation and achieving wider frequency bandwidth by introducing Conductor Backed Coplanar Waveguide (CBCPW) feeding and adopting stubline with notch-staircase shape on radiating patch design. The dimension of the proposed design is 43 × 43 × 1.6 mm3 which reducing 23 % in size compared to the antenna without CBCPW feeding. The antenna operates from 1.85 to 8.37 GHz with 127.6% of fractional bandwidth. It showed a good reflection coefficient with mostly below -15 dB and gain varies from 1 dBi to 5.27 dBi across the impedance bandwidth. The proposed antenna is also experimentally verified, achieving acceptable agreement between the simulation and measurement results. In addition, time domain performance such as input and received signal response and group delay are also observed for the proposed antenna. Owing to its compact size, wideband frequency operation and other acceptable performance, the proposed antenna is suitable for breast tumor imaging implementation.