Résumé:
In the current era, antennas play a significant role in advancing biomedical engineering to enhance both health and quality of life. Various healthcare instruments, such as microwave imaging devices, magnetic resonance imaging machines, pacemakers, deep neural implants, endoscopy tools, and clinical instruments for thermal ablation, leverage the advantages of antennas. Antennas can be implanted, placed on the body, or ingested to transmit diagnostic information from the human body to external monitors and, subsequently, to healthcare professionals through the Internet. Additionally, analyzing variations in the electrical and radiation characteristics of antennas, such as near-field electromagnetic radiation, current density, electric field distribution, magnetic field distribution, specific absorption rate and reflection coefficient, enables non-ionizing and non-invasive disease detection. Important applications of antennas include the detection of brain and breast tumors, and brain strokes.
Circularly polarized (CP) antennas significantly enhance the efficiency of radar systems in medical microwave imaging by mitigating indoor multi-path effects and accommodating various body postures. They also minimize polarization mismatch losses, penetrate lossy dielectric materials in human body tissues, and ensure reliable detection of pathological tissue without being constrained by antenna orientation. While numerous antennas have been documented for biomedical applications, existing ones typically utilize linear polarization and serve a singular purpose, whether for tumor screening, stroke detection, or health-monitoring. Hence, there is a need for innovative high-performance antennas capable of addressing a variety of biomedical applications.
This thesis introduces a mono-static circularly polarized printed monopole antenna (CPPMA) with dimensions of 34 × 28 × 1.5 mm3, designed for applications in the Industrial, Scientific, and Medical (ISM) band. The proposed CPPMA is intended for use in medical microwave imaging and wearable health monitoring applications. Its capabilities include the detection of brain strokes and breast tumors at different positions with various sizes. Additionally, the CPPMA holds potential for deployment in remote health-monitoring systems due to its operation in the ISM band and CP properties.
