Spiral-like implanted antenna for biotelemetry

This paper presents a miniature implanted antenna operated at medical implant communication systems (MICS) band (402-405 MHz) with the dimension of 40×10×1.905 mm³ for biotelemetry. The antenna is fabricated on biocompatible Ceramic Alumina substrates. For simplicity three □ layer human tissues are adopted first. With the special arrangement of the antenna structure, a spiral □ like current distribution is excited and the corresponding electromagnetic wave can be radiated toward the outside of the human body. The antenna achieves a gain of -21.7 dBi, capable of extending the battery life. Furthermore, the frequency response is insensitive to the change of the implanted environment. Finally, a complete human model is used and the results are similar.