Dual-band Slot-SSR Antenna on PLA-printed Substrate for 2.4/5.8 GHz ISM-Band Internet of Things (IoT) Applications

A dual-band antenna based on two radiating rectangular slots working at 2.45 GHz and 5.8 GHz, respectively, with one upper Split Ring Resonator (SRR) to enhance the radiation pattern at 5.8 GHz is proposed in this work. Additionally, one Complementary Split Ring Resonator (CSRR) and three Split Rings (SR) are used to improve the input reflection coefficient. The dual-band antenna covers from 2.39 GHz to 2.52 GHz, and from 5.76 GHz to 5.95 GHz, covering the 2.45 GHz and 5.8 GHz ISM bands. The total size of the proposed antenna is
$\mathbf{31 \mathrm{x}70\mathrm{x}70} \mathbf{mm}^{3}$
. The theoretical gain is better than 8 dBi and 6 dBi, and the radiation efficiency is close to 90% and 80%, in the first and second bands, respectively, from full-wave simulations. The performance of the proposed antenna is very good, which makes it suitable for IoT applications where the size is not a limitation, such as sensors, and LPWAN/WLA modules, health care devices, base stations, and control applications.