Wireless power transfer (WPT) is the key enabler for a myriad of applications,udfrom low-power RFIDs, and wireless sensors, to wirelessly charged electric vehicles,udand even massive power transmission from space solar cells. One of the major challenges in designing implantable biomedical devices is the size and lifetime of theudbattery. Thus, replacing the battery with a miniaturized wireless power receiverud(WPRx) facilitates designing sustainable biomedical implants in smaller volumes forudsentient medical applications. In the first part of this dissertation, we propose a miniaturized, fully integrated, wirelessly powered implantable sensor with on-chip antenna, designed and implemented in a standard 0.18μm CMOS process. As a batteryless device, it can be implanted once inside the body with no need for further invasive surgeries to replace batteries. The proposed single-chip solution is designed for intraocular pressure monitoring (IOPM), and can serve as a sustainable platform for implantable devices or IoT nodes. A custom setup is developed to test the chip in a saline solution with electrical properties similar to those of the aqueous humor of the eye. The proposed chip, in this eye-like setup, is wirelessly charged to 1V from a 5W transmitter 3cm away from the chip.udIn the second part, we propose a self-biased, differential rectifier with enhancedudefficiency over an extended range of input power. A prototype is designed for theudmedical implant communication service (MICS) band at 433MHz. It demonstratesudan efficiency improvement of more than 40% in the rectifier power conversion efficiencyud(PCE) and a dynamic range extension of more than 50% relative to the conventionaludcross-coupled rectifier. A sensitivity of -15.2dBm input power for 1V output voltageudand a peak PCE of 65% are achieved for a 50k load. In the third part, we proposeuda wide-range, differential RF-to-DC power converter using an adaptive, self-biasingudtechnique. The proposed architecture doubles the dynamic range of conventionaludrectifiers. Unlike the continuously self-biased rectifier proposed in the second part,udthis adaptive rectifier extends the dynamic range while maintaining both the highudPCE peak and the sensitivity advantage of the conventional cross-coupled scheme,udand can operates in the GHz range.
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