Measurement of wireless power transfer to deep-tissue RFID-based implants using wireless repeater node

In future wireless implants, tiny sensor nodes may be used for detection and treatment of various diseases and for monitoring therapeutic activities. This requires ultralow-power tiny sensors implantable inside different body organs. This letter presents a biomedical RFID system meant for wireless interrogation of deep-tissue millimeter-size implant sensors. The communication system is based on using a repeater device that amplifies the attenuated downlink power and thus extends sensor read distance. This system enables monitoring of different body organs by placing miniature sensor implants inside them. This letter studies wireless power transmission in this system through fabrication of the antennas and conducting two-port wireless link measurements.