UCLA

Wireless system-on-chip devices are emerging as the most promising solution for future wireless sensing with applications in medical implants and the Internet of Things (IoT). On one side, energy extraction from ambient sources facilitates permanent powering techniques required for long-term operation. On the other side, the high integration capability of commercial CMOS technology opens the opportunity for high-resolution sensing and data communication with a compact form-factor. In this dissertation, My research builds a foundation for joint wireless power delivery, low-power sensing, and wireless communication in such highly integrated systems yielding a paradigm shift in the design and development of future ubiquitous low-power wireless systems.

This thesis presents the design, implementation, and experimental evaluation of integrated wirelessly powered solutions for next-generation medical implants and IoT devices. To this end, First, I leverage the high integration capabilities of CMOS technology and try to develop integrated systems for power delivery, environmental sensing, and wireless data communication. The small power budget available for an integrated solution severely limits its functionality and operating range. Hence, individual wirelessly powered solutions may not be able to satisfy the application requirements of future medical implants and IoT devices. To address this problem, I leverage another important feature of a commercial CMOS technology that is the low fabrication cost. I show how complex tasks such as localization and be realized using a swarm of millimeter-sized integrated chips.

In this dissertation, I introduce the challenges of wireless power transmission to fully integrated systems on CMOS technology and present two types of RF power receiver systems for near-field and far-field electromagnetic region. I propose a comprehensive optimization algorithm for maximizing the power transfer efficiency and choosing the optimum frequency for wireless power transmission.

Next, I present the world's most power-efficient wireless transceiver with an integrated wireless power delivery system. I demonstrate a fully on-chip operation and utilize two sets of loop and dipole antenna for wireless power delivery and data communication, respectively. I will explain how we achieve a 150 Mbps uplink communication data rate under a stringent power budget by introducing a power management technique.

I will then, discuss the opportunities offered by this platform to enhance next-generation IoT and medical devices. In particular, we tackle the limited operating range by forming a synchronized distributed sensor network built from fully on-chip integrated systems. Also, we address the power scarcity challenges in biomedical/environmental sensing by adopting extensive low-power design techniques.

This interdisciplinary research direction incorporates advancements such as applied physics, machine learning, healthcare, and wireless networking.