Fully Textile-Integrated Microstrip-Fed Slot Antenna for Dedicated Short-Range Communications

Abstract

A novel fully textile-integrated antenna based on a slotted short-circuited microstrip line has been designed, manufactured and experimentally validated for its use in automobile upholsteries for dedicated short-range communications. The antenna can be manufactured using an industrial loom and a laser prototyping machine, avoiding subsequent treatments, sewing procedures or coatings. The manufactured antenna presents a central working frequency of 5.9 GHz and a 9.3% bandwith. Good agreement between simulations and measurements has been achieved.

Three-Dimensional Fully Interlaced Woven Microstrip-Fed Substrate Integrated Waveguide

“…Nevertheless, for clarification, the parameters which describe the LM are calculated and presented in this section. Given the epi and ppi parameters and the dielectric characteristics of the employed materials and following the procedure explained in [29,30], the equivalent relative permittivity, ε eq , has been found very close to 1. It means that even though the woven substrate is composed of materials whose relative permittivities are different from ε air , the existence of thick dielectric yarns, placed perpendicularly aligned with the propagation direction, leads to the existence of big air gaps, consequently reducing the value of the equivalent relative permittivity.…”

“…A three-dimensional microstrip-fed TIW using rigid weft threads is proposed for its single-mode operation at a range of frequencies between 7.5 GHz and 12 GHz. The TIW has been designed using the three-step modelling which has already been discussed in [29] and particularised to two steps in [30] due to the use of monofilaments. Figure 1 represents an overview of the Layers Model (LM) associated with the proposed TIW, the coordinate system, the orientation of the electromagnetic (EM) field and the propagation direction.…”

“…The cross section approaches and corresponding dimensions of the different conductive threads are summarised in Table 1. The thickness of the silver coating of each filament, for both types of threads, is given by T c = 0.5 µm, whereas the total diameter of each filament is given by D f = 31 µm, as depicted in Figure 2 Following the procedure described in [30], the skin depth effect of both threads has been analysed. First, the skin depth, δ Sd , is calculated using the minimum frequency, f min = 7.5 GHz, applying Eq.…”

“…According to the procedure referenced in [29,30] and because the PES weft threads remain straight, the different warp threads will conform the woven structure around the weft threads. The ends per inch and picks per inch, commonly known as epi and ppi, parameters employed in both designs are 169.3 and 16.9, respectively, leading to the woven structures which will be explained in detail in Section 5.…”

“…Moreover, in this paper, because the warp threads are flexible, they provide the possibility of creating different warp patterns. As the weft threads are rigid, a constant height of the textile substrate can be achieved [30], leading to a better performance of the TIW.…”