Antenna Parameters for On-Body Communications With Wearable and Implantable Antennas

Characterization of Wearable and Implanted Antennas: Test Procedure and Range Design

“…Based on the assumptions that the body surface can be approximated by flat and/or curved parts and on-body propagation primarily relies on surface waves, on-body antenna parameters that describe the ability of an antenna to excite such surface waves can be established. Following the derivation in free space (FS), the on-body (B) antenna gain can be defined as [10]:…”

“…For on-body communication along the body surface, the characterization is performed circularly in a plane (φ) parallel to the tissue half-space rather than on a sphere (φ, θ) as in FS. Following this approach, the Friis transmission equation for on-body propagation can be reassembled to [10]:…”

“…Recently, we have extended these formulations by defining on-body antenna parameters, such as an angular on-body gain pattern in [10]. The on-body gain pattern establishes a similar metric for on-body propagation as the traditional freespace gain does for classical free-space propagation.…”

“…The on-body gain pattern establishes a similar metric for on-body propagation as the traditional freespace gain does for classical free-space propagation. In [10], it has been successfully used within a numerical modeling framework for the educated design of antennas for hearing aids and pacemakers.…”

“…In this contribution, a test procedure and design of an antenna test range for measuring the on-body radiation pat- tern, as defined in [10], is presented. In contrast to the application-specific path loss measurements performed so far, the presented test method for measuring the on-body gain pattern represents a de-embedded, non application-specific, directional measure of an antenna's ability for exciting onbody surface waves.…”