21.8 An actively detuned wireless power receiver with public key cryptographic authentication and dynamic power allocation

There has been a rapid growth in the number of devices with resonant wireless recharging capability [1–3]. Protecting these devices from harsh transients imposed by counterfeit wireless chargers [4] and ensuring equitable power delivery under heavily skewed coupling [5] remain challenging issues. This paper presents the design of a wireless power receiver that mitigates these disparate issues by leveraging a new detuning technique that does not rely on any switched passives. Public key authentication of genuine chargers is implemented using low-resource Elliptic Curve Cryptography (ECC) [6,7]. Additionally, overcoming the skew in received power imposed by a 4∶1 distance ratio between receivers is demonstrated using a co-operative scheme.