posted Jan 26, 2014, 1:25 AM by Khaled salama
updated Jan 27, 2014, 1:07 AM
Doctoral student Mahmoud Ouda gave a talk about his research at Ohio State University Electroscience lab. He is going to spend 6 month working on a collaborative research project with Prof. Waleed Khalil at the Circuit Laboratory for Advanced Sensors and Systems .
Title: On-Chip RF Power Harvesting Module for Biomedical Implantable Wireless Sensors
Abstract: An On-Chip RF Energy Harvesting module is proposed to deliver power to wireless sensors from incoming RF signals. This module provides a platform for battery-less, miniaturized wireless sensors that can be implanted inside human body to monitor physical properties such as: pressure or temperature and send the reading wirelessly to an external reader. As a battery-less device, it is implanted once and no need for more invasive operation to replace the sensor node or its battery. The proposed RF energy harvesting module includes highly efficient RF rectifier, DC voltage limiter, voltage sensors to enable power management, low dropout regulator (LDO) to provide clean power rail for on-chip transmitter. It is the first fully integrated CMOS-based RF power harvester with an on-chip antenna. The design is optimized for sensors implanted inside the eye to wirelessly monitor the intraocular pressure of glaucoma patients. The chip has been designed and fabricated in a standard 0.18μm CMOS technology. To emulate the eye environment in measurements, a custom test setup is developed that comprises Plexiglass cavities filled with saline solution. Measurements in this setup show that the proposed chip can be charged to 1V wirelessly from a 5-W transmitter 3 cm away from the harvester chip. The energy that is stored on the 5-nF on-chip MOSCAP when charged to 1 V is 2.5 nJ, which is sufficient to drive an arbitrary 100- W load