Beam steering antenna system for 5G and sensor applications

• Main Author: Mahalingam Durga Lakshmi
• Other Authors: Arokiaswami Alphones
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2025
• Subjects: Engineering
• Online Access: https://hdl.handle.net/10356/182660
• Institution: Nanyang Technological University

Wideband beam steering antennas play an essential role in diverse fields such as 5G communications, satellite communications, and next-generation sensors. Conventional beam steering techniques namely mechanical steering, and phase shifters are commonly used for controlling the direction of a radiated beam. However, phase shifters are usually bulky, require higher power consumption, and need a complicated feeding network setup to steer the antenna radiation beam, while a planar leaky wave antenna could be an optimal choice to explore for scanning the radiation in different directions. A leaky wave antenna allows electromagnetic wave propagation in its structure, similar to a waveguide. Still, it radiates or leaks out energy during its interaction with periodic slots of specific geometry over the length of the antenna. The motivation is to design a beam scanning antenna structure that is portable, consumes less power, is inexpensive, and also achieves better antenna steering properties. Usually, the conventional leaky wave antenna could perform scanning in one direction only i.e. either right side or left side and it cannot radiate at the broadside (radiation angle=0°). One such technique to mitigate the above-mentioned limitation of phase shifters and traditional leaky wave antennas is explored in this dissertation, where a multilayered leaky wave antenna (LWA) designed with Composite Right/left-Handed (CRLH) properties are realized on the substrate-integrated waveguide (SIW). This configuration supports a broad range of angles and enables continuous beam steering over the frequency bandwidth. It is designed with a twenty-one-unit cell combination with slots on the uppermost layer and metallic vias. Beam steering is achieved using the frequency sweeping technique. The methodology involves creating a single unit cell and analyzing its dispersion characteristics. Key performance parameters such as S-parameter, gain versus frequency, and radiation efficiency are studied and analyzed. Beam steering angles are analyzed by far-field radiation monitors. This proposed antenna structure can achieve scanning of the radiated beam from -53° till 64° between the frequency interval from 5.48 to 8.215 GHz and a smooth broadside transition where radiation angle=0° without stopband is achieved. The highest gain of the system is 9 dBi. Thereby achieving a wide steering of 117° in total. With better radiation steering, the proposed CRLH-based leaky wave antenna offers a cost-effective and scalable solution with possible integration over the sensing devices and communication system devices.