An Ultrawideband Magnetoelectric Dipole Antenna With Gain Improvement and Its Application in Array Design for Sub-6G Intelligent IoT Communication

Abstract

An ultrawideband magnetoelectric (ME) dipole antenna with stable gain is proposed for sub-6G Internet of Things (IoT) communication systems. While several structures can effectively achieve a wide impedance bandwidth, a critical limitation is that an excessively wide beamwidth often results in gain deterioration over the corresponding frequency range. To address this issue, vertically placed metal plate (VPMP) are introduced to generate out of phase currents and narrow the beamwidth, while folded metal branch (FMB) provide additional vertical radiation, thereby improving gain stability. Consequently, the proposed ME dipole antenna exhibits a 108% impedance bandwidth (1.2–4 GHz) with a measured gain of 7.2 ± 1.9 dBi across the band. Furthermore, based on the proposed antenna element, vertical shorting post (VSP) are employed to introduce out of phase currents for mutual coupling suppression, enabling a 100% operating bandwidth (1.26–3.85 GHz) for the array. In addition, a one-dimensional array prototype is fabricated to validate the proposed design strategy. It demonstrates a scanning range of up to ±45° across 1.26–2 GHz and ±30° across 2–3.85 GHz. Covering most of the L- and S-bands while maintaining stable radiation characteristics, the proposed antenna is a promising candidate for multi-service IoT communication systems including smart home devices, agricultural monitoring, and industrial manufacturing.