Comparable Characterization of Capacitive and Galvanic Intrabody Communication Channel.

Abstract

Intrabody communication (IBC) is a promising modality that leverages the human body as a transmission medium for data communication, enabling low-power and compact solutions suitable for wearable and implantable biomedical devices. This work presents a comprehensive study of IBC channels, jointly evaluating galvanic coupling (GC) and capacitive coupling (CC) in both wearable and implantable configurations. Unlike prior works, which typically consider individual methods or limited configurations, this study combines three different analysis approaches. These are finite element method (FEM) simulations, equivalent circuit modeling, and experimental channel impulse response (CIR) characterization over a broad frequency range. This enables cross-method validation, and consequently the emergence of comparative insights. Full-wave electromagnetic simulations using FEM were performed up to 100 MHz using a multilayered cylindrical model with realistic anatomical and dielectric properties. CIR characterization was performed by transmitting baseband pseudorandom noise (PN) sequences through the modeled and experimental setups. Experimental validations up to 2.5 MHz were carried out using chicken tissue as a biological surrogate. Experimental communication channel gain results closely matched the simulation outcomes, confirming the accuracy of the proposed models and methodologies. Among all tested scenarios, the implantable CC configuration exhibited the highest channel frequency response (CFR) within the investigated frequency range.