Contactless Characterization of a CMOS Integrated LC Resonator for Wireless Power Transferring

Miniaturized implanted circuits must be autonomous, harvesting energy from surroundings or receiving power from an inductive link. Considering the latter, when the implant dimensions are limited to few mm ², the power receiver must be carefully designed so that its efficiency is maximized. If the receiving inductor is integrated in a silicon substrate, a rigorous design methodology should be adopted, because the losses are high, thus degrading the power transmission efficiency. An additional issue arises when such a system needs to be tested, which must happen without invasive techniques. In this article, we describe the contactless characterization of an LC resonator used in an 1.5 mm × 1.5 mm fully integrated wireless power receiver. A quality factor of 20.8 was measured at the resonance frequency 0.99 GHz.