A Low-Profile Broadband Multimode Patch Antenna for 5G Mobile Applications

A low-profile broadband multimode patch antenna is proposed for fifth-generation mobile applications. The proposed antenna is made up of a single metal patch, a FR-4 dielectric substrate layer, an air cavity, and eight metal pins. The patch can form a magnetic wall by adding the eight metal pins, which can also generate a pair of TM
_1/2,0
modes and TM
₁₀
mode. Based on these modes, two narrow rectangles with 0.169λ (about 0.011λ at 3.9 GHz) are etched on the patch, which can simultaneously form two kinds of new modes (TM
_1/2,1
and TM
_1/2,2
) to achieve the broadband operation (3.3–4.2 GHz). To ensure the accuracy of this principle, the antenna sample is made and measured. The measured outcomes are in good accordance with the simulated ones, and the sample can still operate at 3.3–4.2 GHz, covering the 5G N77 band. The in-band total efficiency can reach up to −0.491 dB (89.3%). The maximum gain in the entire band is 9.4 dB.