Flexible and moon-shaped slot UWB implantable antenna design for head implants

摘要

In this paper, we present a novel flexible moon-shaped slot implantable antenna for neural recording systems and head implants. It covers both medical Industrial, Scientific and Medical band (2.45 GHz) and impulse ratio ultra-wideband (IR-UWB) frequency range (3.1-10.6 GHz) for forward and backward telemetry applications. It has a simple and miniaturized structure in comparison with the antennas reported in the other researches. Furthermore, for adapting with natural curvature of human head, a flexible substrate is chosen with a good antenna performance under the bending. The proposed antenna is analyzed in a multi-layer box model of head tissues to speed up the antenna design procedures. On the basis of the simulation results, we achieved the good impedance matching over the desired frequency range (S-11 below - (10) dB). Far-field characteristics are considered, as well. The directivity is in suitable range for UWB short-range communications and its mean value is 3.84 dBi. Finally, to take into account patents' safety regulations and the effective isotropic radiated power restriction in the desired frequency range, the maximum power of transmitter has been calculated. A phantom containing a mixture of sugar and water is used to test the fabricated antenna. The measured parameters are well matched to the full-wave simulation results.