Slot Antennas Integrated into 3D Knitted Fabrics: 5.8 GHz and 24 GHz ISM Bands

Abstract

In the paper, a 3D knitted fabric is used for the design of a circularly polarized textile-integrated antenna. The role of the radiating element is played by a circular slot etched into the conductive top wall of a textile-integrated waveguide. Inside the circular slot, a cross slot rotated for about 45° is etched to excite the circular polarization. The polarization of the antenna can be changed by the rotation of the cross slot. The antenna has a patch-like radiation pattern, and the gain is about 5.3 dBi. The textile-integrated feeder of the antenna is manufactured by screen printing conductive surfaces and sewing side walls with conductive threads. The antenna was developed for ISM bands 5.8 GHz and 24 GHz. The operation frequency 24 GHz is the highest frequency of operation for which the textile-integrated waveguide antenna has been manufactured.

The Influence of Textile Substrates on the Performance of Textronic RFID Transponders

“…Some of them concern constructions that are dedicated to the unlicensed ISM (Industrial Scientific Medical) bands. Typically, these antennas are made by combining (a) classic conductive materials with a textile base (e.g., copper foil or screen-printed layer on cotton [ 14 ] and other substrates [ 15 ]) or (b) innovative conductive textile materials (e.g., conductive polymers, electrotextiles, graphene sheet, fabrics with metal threads [ 16 , 17 ]) with classic textiles (e.g., graphene sheet with denim or felt [ 13 , 18 ]). In addition, the integration of a typical flexible antenna (e.g., made on polyethylene terephthalate PET foils) with fabrics is frequently used [ 18 , 19 ].…”

Three-Dimensional Printed Annular Ring Aperture-Fed Antenna for Telecommunication and Biomedical Applications

“…Moreover, 3D printing is a unique venue for RF circuits, promising especially novel antenna design for 5G telecommunications systems [7]. It can be employed to ease the implementation and realization process of a complex substrate of RF components [8][9][10][11][12][13][14][15][16][17]. However, some challenges, such as soldering, are associated with the 3D-printed substrate.…”