A quadband implantable antenna system for simultaneous wireless powering and biotelemetry of deep-body implants

Abstract

This study proposes a wireless power transfer (WPT) system consisting of a patterned WPT transmitter (Tx), an efficient voltage doubler, and an antenna integrated with the system. The WPT Tx had a size of 6 cm × 6 × cm and was optimized to focus the power on the deep-tissue implants at 1470 MHz. The voltage doubler was optimized at 1470 MHz, had a small size of 5 mm × 10 mm, and exhibited high RF-to-DC conversion efficiency of 80% at 2 dBm RF input power. Moreover, the implantable antenna occupies a small volume of 8.43 mm3 and supports quadband operations: 403 MHz, 915 MHz, 1470 MHz, and 2.4 GHz. The fabricated prototypes were measured individually in minced pork, ASTM model, and in the saline-filled 3D head phantom. It is evident from the experimental results that the system can transfer 6.7 mW power to a 5 cm deep millimeter-sized implants.