A Miniaturized Tri-Band Implantable Antenna for ISM/WMTS/Lower UWB/Wi-Fi Frequencies

Area of Science:

• Biomedical Engineering
• Electromagnetics
• Antenna Design

Background:

• Implantable antennas are crucial for wireless medical devices.
• Existing antennas often lack the required bandwidth, size, or efficiency for diverse applications.
• Need for a compact, multi-band antenna compatible with various wireless standards.

Purpose of the Study:

• To design and validate a compact antenna for implantable devices.
• To achieve broad frequency coverage including ISM, WMTS, UWB, and Wi-Fi bands.
• To ensure the antenna meets stringent safety and performance criteria for medical use.

Main Methods:

• Designed a novel antenna with an asynchronous-meandered radiator, parasitic patch, and open-ended square ring ground plane.
• Simulated antenna performance in rectangular and cylindrical phantoms at various depths and orientations.
• Fabricated a prototype and measured its reflection coefficient and radiation patterns in fresh pork tissue.

Main Results:

• The antenna achieved a compact volume of 75 mm³.
• Demonstrated exceptionally wide bandwidths: 181.8% (0.86 GHz), 9.58% (1.43 GHz), and 285.7% (UWB/Wi-Fi).
• Achieved high gains (-26 dBi to -14.2 dBi) and SAR values well below IEEE safety limits.

Conclusions:

• The proposed antenna is a highly suitable candidate for implantable wireless devices.
• It outperforms existing designs in terms of size, bandwidth, gain, and safety.
• The antenna's versatility supports diverse wireless communication technologies for medical applications.