TOPOLOGICAL EXPLOITATION OF ELECTROMAGNETIC METASURFACE AND WEARABLE ANTENNA SYSTEM
Restricted (Penn State Only)
- Author:
- Wu, Yuhao
- Graduate Program:
- Electrical Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 02, 2023
- Committee Members:
- Madhavan Swaminathan, Program Head/Chair
Douglas Werner, Chair & Dissertation Advisor
Xingjie Ni, Major Field Member
Sawyer Campbell, Major Field Member
Ramakrishnan Rajagopalan, Outside Unit & Field Member - Keywords:
- Metasurface
Topological Photonics
wearable antenna
PT-symmetry - Abstract:
- The use of artificial materials to manipulate light-matter interaction by modifying subwavelength lattice has garnered significant research attention across various wave-modulation and investigation fields. Metasurfaces, a newly emerging 2D counterpart composed of in-plane subwavelength metaatoms, offer high feasibility and an ultrathin profile for manipulating wave properties. Meanwhile, there is a growing interest in exploring the topological nature of photonic systems. Bound states in the continuum (BIC), non-radiative singularities that are of diverging quality factor and rich topological property make ideal candidate for optical modulation. This dissertation explores several functional aspects of BIC-based topological metasurface, including all-optical modulation based on reflective metasurfaces and ultrafast optical vortex generation and modulation on transmissive metasurfaces. On the other hand, wireless body area networks (BAN) and wearable electronic systems are rapidly developing. A lightweight, low-profile communication system is desired that is highly flexible, and robust. To achieve this goal, several technical specifications need optimization such as robustness to human-body loading effect and structural deformation, mutual coupling between channels and radiation efficiency in a small form factor. In this dissertation, several advanced on-body communication antennas are presented that enable on-body/off-body data channels and seamless integration into wearable garments, including a monolayer dual-port orthomode full-duplex antenna and a surface plasmon polariton based leaky textile wave antenna. Furthermore, inspired by the topological analysis in the continuously periodic photonic devices, a new topology is proposed and analyzed for the discrete wireless power transfer (WPT) systems. The power efficiency limit is achieved with generalized parity-time symmetry in the proposed scheme under dynamically varying coupling conditions.