Propagation Loss Reduction Between On-Body Antennas by Using a Conductive Strip Line

Abstract

This letter proposes a very simple solution to reduce the propagation loss between two antennas/sensors on body at 2.45 GHz by utilizing a flexible conductive strip line (CSL). The performance of the CSL is comparable to that of the free-access transmission line in the work by Tran et al. in some certain cases. The transmission improvement by the CSL is verified by measurement results on a perfect electrical conductor plane, on a phantom, and on a real body more than 20 dB for non-line-of-sight scenarios. Dimension parameters of the CSL are optimized so that the highest improvement by the CSL can be achieved and it is easy to be integrated into clothes. Moreover, the specific absorption rate is satisfied when the CSL is deployed near body.

Broadband Low-Loss On-Body UHF to Millimeter-Wave Surface Wave Links Using Flexible Textile Single Wire Transmission Lines

“…However, the on-body attenuation cannot be ignored, where low-loss on-body links, especially in the mmWave spectrum, are only achievable using highly directional antennas such as nontextile horns [21]. To reduce the on-body losses, a conductive textile stripline was proposed, reducing the losses between two on-body patch antennas by at least 10 dB [23]. Nevertheless, this approach was limited in bandwidth and only demonstrated at 2.4 GHz.…”

Embroidered Spoof Surface Plasmon Polariton Transmission Line for Wireless Body Sensor Network

“…For improving the propagation characteristics of on-body communications, Non-Line-Of-Sight (NLOS) links were involved by integrating supplementary waveguides on clothing [10][11][12][13]. By using a strip line or a segmented coplanar waveguide, a 20 dB improvement of the transmission was achieved compared with transmission between two patch antennas in free space.…”

“…By using a strip line or a segmented coplanar waveguide, a 20 dB improvement of the transmission was achieved compared with transmission between two patch antennas in free space. Moreover, such wearable waveguides can be wirelessly connected by coupling to antennas avoiding the irrelevant and problematic need of connectors in smart textiles [10,11,14]. A wearable and wireless network based on Spoof Surface Plasmon Polariton Transmission Line (SSPP TL) was also proposed with a 30 dB enhancement of the transmission efficiency together with an electromagnetic field localisation within 10 cm of the body [12].…”