Broadband Cross-Slotted Patch Antenna for 5G Millimeter-Wave Applications Based on Characteristic Mode Analysis

This article proposes a wideband differentially fed dual-polarized magnetoelectric (ME) dipole for millimeter-wave (mm-Wave) applications. Various electric and magnetic characteristic modes of a slotted patch antenna are investigated and utilized effectively to create a stable broadside radiation pattern, covering fifth-generation (5G) frequency bands from 24.25 to 40 GHz. To implement this, the lifted ground (LGND) concept is applied to achieve a 57.1% impedance bandwidth for a single antenna element. In addition, the three resonances of the antenna can be manipulated independently. The use of differential feeding allows more than 36 dB of port-to-port isolation across the entire operating band. The measured gains of the single element and
$2\times $
2 array are 8.4 and 13.4 dBi, respectively. Also, the measured results indicate symmetrical E- and H-plane radiation patterns and cross-polarization levels lower than −26 dB. With the favorable electrical performance, compact size, simple structure, and low-cost fabrication, the proposed ME dipole is a promising candidate for mm-Wave Antenna-in-Package (AiP) applications.