Radiation characteristics of miniature silicon square spiral chip antenna for implantable bio-MEMS sensors

In this paper, a miniature (1x1 mm) printed square spiral chip antenna for contact-less powering and RF telemetry from implantable bio-MEMS sensors is characterized at 235 MHz. The antenna is fabricated on a high resistivity silicon wafer and has a serrated ground plane on the opposite side to mitigate image current effects. The experimental results include the radiation patterns of the chip antenna and the received signal strength at the output of a larger (10x10 mm) printed square spiral pick-up antenna

I. INTRODUCTION

The robotic and human exploration of the space program at NASA seeks to develop implantable wireless sensors to monitor the physiological parameters of humans during space flights[1]. This focus is rather unique when compared to efforts by other investigators, which have been mainly in the area of electromagnetic-wave interaction with biological systems, hyperthermia treatment of cancer, RF/microwave applications in medical treatment and biological effects [2].