Slotted Patch Antenna with Wide Bandwidth for In-body Biotelemetry Applications

Abstract

This paper proposes a slotted patch antenna with wide bandwidth covering ISM frequency band (2.40-2.48 GHz) for implantable biotelemetry applications. A homogeneous skin phantom (HSP) model proves the usability of the proposed antenna in in-body environments. At a resonance frequency of 2.42 GHz, the design shows an S11 parameter of -35.56 dB, a percentage impedance bandwidth of 66.6% (2-4 GHz), and the maximum peak gain of -24.80 dBi. To validate the simulated results, the designed antenna was fabricated and measured, showing good compliance with the expected results. To ensure tissue safety, a specific absorption rate (SAR) is simulated for the proposed antenna which satisfies the requirements of IEEE standards, with a value of 87.75 W/kg for 10 g of tissue. The proposed antenna shows a telemetry range of 11 and 6.3 m at 7 kbps and 100 kbps data rates, respectively. The key features of the proposed antenna include the following: miniaturization, good S parameters, wide bandwidth, low SAR, good telemetry range, and high gain.

Keywords

• biotelemetry
• implantable antenna
• ISM band
• specific absorption rate (SAR)