A Dual-Band Textile Eighth Mode SIW Antenna for Wearable Applications

This work presents a compact dual band textile wearable antenna in substrate integrated waveguide (SIW) technology. The antenna is based on a SIW square cavity, and its small size has been achieved exploiting the magnetic field symmetry of the cavity, which allows to reduce its size to 1/8 of the full cavity with the so called "Eighth-mode SIW configuration". The presented dual band antenna is designed for Long Range (LoRa) applications, and its working frequency covers the European (863-870 MHz) and the North American (902-928 MHz) LoRa bands. The proposed wearable SIW antenna is compact, low-cost and relatively easy to fabricate. Moreover, its robustness and isolation with respect to the human body coupling are very good. The antenna design has been performed using CST Studio Suite, and the agreement between numerical and experimental result is satisfactory.