Narrowband RF Localization Circuits and Systems

Abstract

This dissertation focuses on the design and implementation of wireless communication circuits and systems for IoT applications, aiming to build a miniaturized IoT device with low power consumption and advanced features. Several challenges need to be addressed. First, the increasing number of devices operating in the limited radio spectrum resources drives the need for improving out-of-band filtering to eliminate interference. Second, the limited battery capacity and driving power restrict the functionality of IoT devices, necessitating new circuits and systems co-design to enhance performance. Third, the power-hungry and bulky off-chip components challenge the system's power and form-factor constraints. This dissertation proposes three works in circuits and systems, especially localization systems, to address those issues. The first work introduces a highly reconfigurable analog-FIR filter with a sharp transition and high rejection to address the IoT device spectrum congestion issue. The second work proposes a long-range narrowband RF localization system featuring a PLL-less frequency hopping receiver front-end with a novel signal processing technique, enabling an unprecedented long-range localization service with a small form factor of the tag device. Lastly, a more comprehensive version of a PLL-less and crystal-less frequency hopping receiver is proposed. We introduce a novel signal processing technique to resolve the unstable sampling clock issue, enabling a compact and fully integrated receiver. The three works present in this dissertation provide solutions to IoT challenges and broaden IoT applications.