Design and Delevopment of a Dual-band PIFA Antenna for Brain Interface Applications

This paper studies a dual-band planar inverted-F antenna (PIFA) on a flexible thin film for wireless brain interface applications due to the high demand for effective implantable brain machine interface microsystems including brain computer interfaces (BCIs). The antenna operates at two frequency bands, medical implant communications service (MICS) and wireless medical telemetry service (WMTS) bands. The structure is designed for the power efficiency without violating the specific absorption rate (SAR) limits. The flexible DuPont Kapton with the thickness of 0.25 mm is used as the substrate and the silicon adhesive is applied as the superstarte with the same thickness to cover the antenna. The optimized antenna model, after tuned by a genetic algorithm in a simplified six-layer phantom model, is 20.2 mm x 14.6 mm. Simulated return losses in the simplified phantom and the realistic head model are compared. The prototype is built and tested in a brain mimicking solution. The results demonstrate that the prototype successfully provide an acceptable result between simulation and measurement. The maximum input power for the PIFA is up to 1.96 mW for 403.5 MHz and 1.78 mW for 1413.5 MHz.