Improved Fabrication Methodology for Foldable All-Textile Cavity-Backed Slot Antennas

In this work, a new fabrication methodology for the production of textile cavity-backed substrate integrated waveguide slot antennas is proposed. This methodology involves laser cutting the entire electrotextile part in one single patch, which is then folded around a dielectric textile substrate. Since this procedure realizes the vertical cavity walls by slabs protruding from the electrotextile patch, heavy metal eyelet vias can be omitted, leading to a drastic reduction in antenna weight and improving wearability. Furthermore, this method is more suitable for automated mass production compared to existing design procedures: it requires fewer manipulations, diminishes alignment errors and suffers less from textile cutting inconveniences such as inaccuracies and textile fraying. This leads to a higher yield, and thus lower production costs. As a proof of concept, a broadband multi-moded cavity backed slot antenna is realized in this novel fabrication methodology. Measurements show a broadside gain of 6.5 dBi, a radiation efficiency of 70% and a fractional impedance bandwidth of 16%.