A Compact Multi-Mode Antenna Design Based on Metasurface for Wideband Applications

This paper presents a novel approach to design a compact wideband metasurface (MS) antenna with multi-mode resonance for Internet of Things (IoT) applications. The proposed antenna incorporates an aperiodic MS structure and an aperture-coupled feeding structure, operating within the frequency range of 2.15 GHz to 3.84 GHz, covering n7, n38, n41, and n78 frequency bands. Initially, an MS resonant antenna is designed based on the left-handed dispersion characteristics of metamaterials, generating TM (-10) and TM (-20) modes, which are then merged. Subsequently, the unit structure is adjusted to transform the antenna into an aperiodic structure, resulting in the generation of the TM (-21) mode. The working frequency is from 2.15 GHz to 3.84 GHz with 56 % fractional bandwidth. The three negative resonant modes are cleverly combined to enable broadside patterns with a maximum realized gain of 4.22 dBi. Besides that, its simultaneous wideband operation and miniaturized form factor makes this design unique compared to previously reported literature.