The growing number of widely-distributed IoT devices presents new challenges in power delivery. Existing frameworks for charging electronic devices, be they wired or wireless, either end up limiting the amount devices can be shrunk due to the size of standardized connectors or end up restricting their free placement. Moreover, they are not optimized for handling multiple receivers connected to the same charger.
I will first talk about a receiver for device-to-device wireless charging. The receiver dynamically measures the end-to-end system efficiency and adjusts the input impedance it presents to the wireless power transmission system in order to track the maximum efficiency point. Next, using duty cycled control of the rectifier, I will present a technique to detune a resonant receiver from the frequency of operation. This can be used to selectively detune receivers in a one transmitter-multiple receiver scenario to ensure power delivery to farther receivers by detuning the closer receivers. Further, a receiver can use cryptographic authentication schemes along with detuning to ensure it is coupled to a legitimate transmitter that can be trusted to provide safe operation.
Thesis Supervisor: Anantha Chandrakasan