Design and Parametric Optimization of A Compact Meander-Line Planar Inverted-F Antenna for IoT Applications

Abstract

Small and efficient dual-band antennas are desirable more than ever in the era of the Internet of Things (IoT) where more and more devices are required to operate on multiple wireless standards. However, it is a challenge to design a device to operate reliably at 2.45 GHz and 5.80 GHz in a small device footprint. In this paper, a compact meander-line Planar Inverted-F Antenna (PIFA) for Wi-Fi and Bluetooth based IoT devices is designed and fully-wave simulated. The proposed antenna is fabricated on a standard FR-4 substrate, and the overall size of the antenna is (25 × 10) mm, which is about 70% reduced in size compared with a conventional quarter-wave patch for the same frequency range. The defected ground structures (DGS) and parasitic elements are not used and the structure is simple with low manufacturing requirements. Antenna is modelled and optimized using CST Studio Suite with the frequency domain finite element method (FEM) solver and a systematic parametric optimization process. The optimized design has resonances at 2.45 GHz and 5.80 GHz with return losses of −18.4 dB and −14.1 dB, respectively. Both operating bands have a VSWR below 2, which is a good impedance match. The antenna gains 2.10 dBi and 1.83 dBi and the radiation efficiencies are 66.2% and 53.2% at 2.45 GHz and 5.80 GHz respectively. The results demonstrate that a single element meander-line PIFA can be used to obtain a dual-band operation with good radiation performance in a compact IoT device in the 2.45 GHz and 5.80 GHz bands, with a low cost.