Design and Performance Analysis of a Purely Textile Proximity Fed Microstrip Patch Antenna for On-Body Wireless Communications

Wearable textile antennas: investigation on material variants, fabrication methods, design and application

“…In this technique, two dielectric substrates are used so that the feed line is located between the two substrates and the radiating area is located on the top substrate. The proximity feeding mechanism has the distinct advantage that any radiation is shielded from the feed line and potentially re-radiated from the patch, resulting in good cross-polarization and body isolation Table 3 Comparison of various feeding mechanism in the literature and their advantages and disadvantages for textile antennas ( Del-Rio-Ruiz et al, 2018;Duffy, 2000). Compared to other feeding methods, the use of a proximity feed can not only improve the operating BW of the antenna (Grilo & Correra, 2015), but also reduce the footprint of the design, making it more suitable for integration into a portable system (Martinez et al, 2020).…”

“…In general, interaction between the feedline and the radiating conductor can be avoided using the aperture technique, leading to a reduction in spurious radiation. The main disadvantage is the high back radiation, which is undesirable for body worn communications (Del-Rio-Ruiz et al, 2018). In aperture coupled feed technique the feed line is directly in contact with the tissue and hence absorption is actually larger, which results in a high level of Specific Absorption Rate (SAR) under the antenna (Leduc & Zhadobov, 2017).…”

Planar Textile Off-Body Communication Antennas: A Survey

“…Multilayer microstrip feeding techniques increase the BW of the antennas, they are robust to bending, but the manufacturing process needs to be more precise due to the required multilayer alignment [32,40,49,63]. According to the latest literature, there have not been any designs found with parasitic elements or slots in the radiator patch.…”

“…Several BW enhancement techniques have been proposed for microstrip antenna topologies: (I) The modification of the patch creating complex designs to combine different resonant frequency bands [7,36,41,43], (II) the insertion of slots in the radiator patch [6,36,42,50,52,69], (III) the addition of parasitic elements to the radiator patch layer [7,36,40,42], and (IV) the modification of the feeding technique [34,40,42,49,63,74].…”

“…Nonetheless, a few embroidered techniques have been reported in the latest literature for off-body communication antennas [64,77]. The layer attachment is performed using glue or dielectric threads (sewing) [32,39,47,49,51,54,56,57,63,73]. The sewing of the antennas can be hand-made [51,57] or machine-made [32,39,49].…”