Investigation of Dominant Wave Mechanism and Optimal Antenna Excitation for Body-Centric Wireless Propagations

Abstract

Vertically-and horizontally-polarized antennas were investigated for on-body to on-body (OB2OB), in-body to in-body (IB2IB), and on-body to in-body (OB2IB) wireless propagations at frequencies of 915 MHz and 2.45 GHz. Theoretical formulations, simulations, and measurements were employed to study the effect of source antenna orientation on the attenuation of the radio frequency (RF) wave as it propagates around, inside, and through the body near the torso region. The results show that the vertical polarization is preferred for OB2OB communication, and the horizontal polarization is better for IB2IB communication. Furthermore, the dominant propagation mechanism and optimum antenna excitation for OB2IB communication are identified to be distance-dependent. The horizontallypolarized dipole is preferred at a shorter distance while the vertically-polarized dipole is preferred at a larger distance away from the source. The observed results were explained using the estimated attenuation rates of the different propagation mechanisms.

Wearable Antennas for Virtual Reality Cross-Body Links

“…Monopole and dipole antenna polarized perpendicular to the skin have been characterized as good candidates for exciting creeping waves from previous studies [15], [17]- [19]. However, those antennas inevitably are too tall for the practice use in the compact and low-profile consumer electronic devices and thus not fit the above-described VR antenna consideration.…”

“…As discussed in [5], [15], [17]- [19], creeping wave is in favor of antenna that excite E-field that is perpendicular to the human body. Many of those studied uses dipole antenna with different orientation for the polarization comparison, however, the inherited height difference in different orientation might also play a role in the results as Fig.…”