Novel Antenna Design for Surface Wave Suppression in Microwave Breast Screening

One of the challenges of antenna design for microwave-based breast screening systems is to minimize the surface waves propagating at the interface between the substrate and the biological tissue. The surface waves become additionally pronounced inside the substrate with a confining ground plane, which is required for unidirectionality and blocks environmental radiation. This paper introduces a simplified human breast model and presents a quantitative analysis of the existing surface waves. Then, we propose an array of 16 cavity-backed patch antennas with parasitic elements, designed to operate in the 3.1-5.1 GHz range. Each antenna element is optimized to function next to the breast tissue. Full-wave simulations reveal that the proposed antenna array achieves higher unidirectionality and suppressed mutual coupling levels. In addition, the design offers improved bio-compatibility when compared with the previous designs, as it employs the SYLGARD™ 184 silicone elastomer PDMS substrate.

I. Introduction

Breast cancer is estimated to have caused approximately 28,000 deaths in Canadian women in 2022 [1]. The timely intervention has shown to be effective in reducing the fatality rate, from 73% for a stage 4 diagnosis to only 1% for a stage 1 diagnosis. Microwave radar technology (MWR) offers safe, compact, wearable, and cost-efficient solutions while bypassing the downsides of ionizing radiation and discomfort of mammography, and high cost and limited accessibility of magnetic resonance imaging (MRI) [2].