Quality aware synthesis of antenna systems for simultaneous wireless information and power transfer in IoT applications

Abstract

Recent advancements in wireless communication technologies and electronics manufacturing have enabled the development of low-cost, low-power, miniaturized, and multifunctional Internet of Things (IoT) devices. These devices, part of IoT networks, communicate with each other and relay data to a remote Access Point (AP) via wireless technologies such as Bluetooth Low Energy (BLE), WiFi, and ZigBee. They find applications in diverse fields including environmental monitoring, smart cities, smart agriculture, intelligent healthcare, smart car parking, and tracking systems. The deployment of large-scale wireless sensor networks (WSNs) with high device density generates substantial data traffic between nodes and the AP, necessitating a communication system with wide bandwidth and high capacity at the AP. However, the dense network of WSNs leads to high interference, which limits the achievable capacity and degrades the signal-to-interference ratio (SIR). This reduction in SIR adversely affects effective coverage and link quality, resulting in increased energy consumption due to frequent re-transmissions required to maintain communication reliability. Consequently, energy consumption and the overall lifetime of the IoT devices are significantly impacted. To address the challenges of low SIR and capacity, techniques such as frequency reuse and high-gain antennas are utilized, though they offer limited spatial coverage with adequate SIR. Additionally, the limited battery capacity of miniaturized IoT devices makes battery replacement cumbersome and costly. To enhance sustainability, wireless power transmission (WPT) techniques, particularly within the IoT framework, offer a promising solution. WPT enables wireless recharging of batteries and, with sufficient power transfer, facilitates battery-less operation of ultra-low-power WPT enabled IoT devices, making power delivery both cost-effective and convenient. Furthermore, the simultaneous wireless information and power transfer (SWIPT) approach can be employed to power IoT devices through base stations and dedicated RF energy sources, promoting a sustainable wireless communication network. This thesis focuses on the quality-aware synthesis of antenna systems for access points (AP), RF energy transmitters, WPT-enabled IoT devices, and SWIPT-enabled IoT devices and relay nodes, with the aim of enhancing communication link quality and ensuring the sustainability of IoT applications. The proposed antennas aim to address the limitations imposed by interference and limited battery capacity of IoT devices, thereby enhancing the overall performance and longevity of IoT networks.