Dual-Band Implantable Antenna Loaded with Patch Slots for Wireless Biotelemetry Systems

This paper presents a dual-band implantable antenna with coaxial probe feeding for wireless biotelemetry applications. The antenna features spiral patches, resulting in a compact size of 27 × 14 × 1.6 mm³. It can operate in two different frequency bands, 241–641 MHz and 1.17–2.06 GHz, providing coverage for the medical implant communication service (MICS) band and the industrial, scientific, and medical (ISM) band. This simple design offers improved return loss and higher bandwidths that are achieved by incorpo-rating patch slots and shortening pins in spiral patches, representing a significant contribution to the field of dual-band antenna design for wireless biotelemetry systems. In the human body phantom model, the SAR values of 48.9 mW/kg and 1.19 W/kg are achieved, which satisfy the IEEE standard safety constraints. An experimental prototype of the proposed antenna is fabricated, demonstrating acceptable return loss and VSWR.