A Pseudo-Normal-Mode Helical Antenna for Use With Deeply Implanted Wireless Sensors

A pseudo-normal-mode helical antenna as part of a deeply implanted wireless sensor was designed. Justification for using this type of antenna along with simulation, in vitro and in vivo experimental results are presented in this communication. The circumference of the helical coil is 0.43 lambda(ib) (wavelength in-body) and its height is 0.23 lambda(ib) which includes substantial insulation. While losses from such a deeply implanted antenna are inevitable, the work presented here shows accurate frequency tuning can be achieved prior to implantation. The relative size, safety of use and results presented here make this pseudo-normal-mode helical antenna an excellent candidate for use with deeply implanted wireless sensors.