A Sub-Mw Antenna-Impedance Detection Using Electrical Balance For Single-Step On-Chip Tunable Matching In Wearable/Implantable Applications

Wearable/implantable devices, e.g., heart-rate-monitor straps and implanted wireless sensors, need to be ultra-low-power (ULP), compact, and also robust against the proximity effect, which can significantly degrade the antenna and front-end performance and hence battery lifetime. A fully integrated adaptive front-end with a tunable matching network (TMN) using low-power and fast impedance detection is highly desirable for robust and efficient operation.