Study on the Impact of Human Arm Tissue on Wearable Device Antenna Performance and Optimization Strategies

This paper investigates the influence of human arm tissue on wearable device antenna performance and proposes optimization strategies to enhance the communication efficiency. Base on the four-term Cole-Cole model and a multi-relaxation dispersion model of biological tissues, we analyze the electrical properties of arm tissue in the frequency range from 0.3 to 10 GHz. Through Ansys HFSS simulations, we compare the reflection coefficients, gain, and electromagnetic field distributions of half-wave dipole and loop antennas in both parallel and perpendicular configurations relative to the arm. Results demonstrate that when the antenna maintains a distance of at least 10 mm from the arm surface, the arm acts as a reflective back ground plane with increased gain as 5.4 dBi for the dipole and 5.16 dBi for the loop antenna. Vertical polarization exhibits reduced interaction with the arm at close proximity, making it preferable for body-to-body communication. This study provides a theoretical guidance for the design and optimization of wearable antennas.