Strong-coupling ultra-wideband low-profile array antenna

The invention discloses a strong-coupling ultra-wideband low-profile array antenna, and belongs to the field of radar antennas. The antenna mainly comprises a metal reflecting plate, a dielectric layer, a metal radiation layer, a metal matching layer, a longitudinal feed balun and a radio frequency coaxial connector. Wherein the metal radiation layer is composed of three rotationally symmetrical blade-shaped metal arms, and the metal matching layer is formed by periodically arranging a plurality of slotted hexagonal structures. The antenna units are arrayed according to the regular triangular grid, the low-frequency impedance bandwidth of the array antenna is expanded due to the fact that the three radiation metal arms among the three adjacent antenna units in the array form a strong coupling structure, and meanwhile the impedance bandwidth of the array antenna is further increased by adopting the broadband feed balun and the capacitive metal matching layer. And finally, the ultra-wideband and low-profile cha