Haoling Li MS Thesis Defense

Title: Ultracompact and Conformal Magnetodielectric Antennas

Committee Members:
Prof. Nian-Xiang Sun (Advisor)
Prof. Xufeng Zhang
Prof. Marvin Onabajo

Abstract:
Novel approaches are needed for improving antenna performance, enhancing efficiency, and reducing the size, profile, number, and signature of antennas. Efficient conformal antennas are increasingly replacing traditional antennas across platforms such as ships, aircraft, and human interfaces. Magnetodielectric antennas made with high-hesistivity magnetic materials are getting more and more attention. Defined as the maximum magnetic conductivity, hesitivity is directly related to the radiation efficiency of magnetodielectric antennas, with a higher hesitivity corresponding to higher attainable efficiency. In this study, new ultra-compact conformal magnetodielectric antennas are demonstrated, employing commercially available ferrite ceramic substrates. Through rigorous simulation and fabrication, a comprehensive comparison of our magnetodielectric antennas with reference monopole antennas demonstrated superior efficiency, enhanced gain, bandwidth, and a substantial reduction in antenna size compared to monopole antennas. State-of-the-art hesitivity as high as 6×10^6 Ω/m has been reported in CoZrNb alloy films, with an expectation of further 10× improvement in thin carrier substrates. This study forecasts the potential development of new magnetic materials with higher hesitivity, leading to further advancements in magnetodielectric antennas with enhanced radiation efficiency and ground plane immunity.