Compact Implantable Antenna for Enhanced Bio-Telemetry Communication in the MICS Band

A remote healthcare system allows patients to be monitored and diagnosed at home; however, reliable wireless link is essential to make it possible. This study proposes a miniaturized implantable antenna resonating at 401-406 MHz, medical implant communication service band. The proposed implantable antenna has a 12 mm × 12 mm × 0.64 mm (92.16 mm3) compact footprints and is fabricated on a bio-compatible Roger R03010 material. To improve the safety, superstrate and a silicon coating around the antenna are employed to completely insulate the antenna from the surrounding tissues. The finite difference time domain and finite-element methods were utilized to optimize and simulate the proposed antenna, followed by fabrication and testing. For better validation, simulations of the proposed implantable antenna, including reflection coefficient, gain, and scattering parameters were performed within a three-layer body phantom while the measurements were conducted inside minced pork. The developed prototype of the implantable antenna exhibits 74 MHz measured bandwidth and -31.6 dBi measured gain at 402 MHz. Further, the specific absorption rate analyses were performed for safety concerns and found to be within the standard limits. Both the simulated and measured results exhibit good agreements, with the overall performance reaching the state-of-the-art.