Mutual Coupling Reduction in Circular Array Antenna Sensors Using via and EBG for Enhanced Breast Cancer Detection

[fig1-abstract] Mutual coupling in circular array antenna sensors used for microwave imaging can degrade the accuracy and quality of breast cancer detection. This letter presents the design of a printed monopole antenna integrated with a via and Z-shaped slot electromagnetic band gap (PMA-VZEBG) structure to reduce mutual coupling in a circular array configuration. A 1 ×8 PMA-VZEBG circular array was simulated and experimentally validated, demonstrating that the integration of the via and ZEBG structure effectively suppresses mutual coupling to below - dB across the entire operational frequency range of$2.22-5.77$GHz in a circular array. As a proof-of-concept, imaging experiments using a breast phantom and a delay-and-sum algorithm indicated the potential impact of reduced mutual coupling on imaging performance, achieving a localization error of 1.2 mm and a contrast-to-noise ratio (CNR) of 3.85.