Directivity enhancement of microstrip antennas for high-resolution brain tumor imaging using characteristic modes theory and the confocal microwave image reconstruction algorithm

Abstract

The increasing prevalence of brain tumors necessitates the development of advanced diagnostic techniques to enhance detection and characterization. This paper presents innovative methodologies for designing and optimizing antenna characteristics using characteristic modes theory (CMT), specifically adapted for high-resolution imaging in medical applications. Our research focuses on the critical goal of improving the accuracy and precision of brain tumor detection through a confocal microwave image reconstruction algorithm. The study begins with an in-depth modeling of essential antenna elements, examining their behavior to understand their interactions within the overall structure. This comprehensive analysis enhances our understanding of antenna performance and characteristics. The introduction of CMT is pivotal, as it facilitates the identification of resonance frequencies that exhibit exceptional radiation efficiency. Moreover, the antenna's directivity is significantly enhanced through a thorough investigation of the effects of various substrate materials and patch shapes on the performance of the radiated antenna modes. This study prioritizes the optimization of the dominant directive mode to improve tumor imaging resolution, ultimately leading to superior quality imaging results. To compare and analyze the impact of different antenna directivity modes on the imaging resolution of brain tumors, two optimized antennas with distinct patch shapes and radiation patterns are integrated into a microwave imaging system. This advanced system is carefully designed to accurately locate and characterize brain tumors, enhancing diagnostic precision. The confocal imaging algorithm demonstrates that the dominant mode with high directivity radiation produces high-resolution images that significantly improve tumor detection and diagnosis.