Application of Coupled Modes in Compact Antenna and Reflector Array

Author(s): Tian, Haozhan | Advisor(s): Itoh, Tatsuo | Abstract: Compact antenna has been widely used due to its advantage of compact size and low fabrication cost. With the development of communication, antennas with unique radiation features are required for different scenarios. For example, beam steering is desired for 5G; while endfire radiation is for vehicle-to-vehicle communications. These requirements bring new challenges to the design of the compact antenna. In order to realize the features, designers always have to compromise on size, robustness, or fabrication cost. To alleviate this problem, we propose a new design method that applies coupled modes into the compact antenna designs. In this dissertation, beam steering antenna, endfire antenna with vertical polarization, and circularly-polarized antenna are demonstrated respectively. All the proposed antennas remain compact, robust, and cost-efficient. In addition, the coupled-mode concept is further extended to design reflector array. The proposed retro-reflective grating array works for wide-band incoming wave with any polarization. Other possible applications of the proposed concept are also discussed.