An antenna array device, comprising: a substrate, comprising a first surface and a second surface; a plurality of antenna elements (110a and 110b), disposed on the first surface, wherein the plurality of antenna elements (110a and 110b) have a first polarization direction and a second polarization direction opposite to the first polarization direction, and the plurality of antenna elements (110a and 110b) have a first via (vial) respectively; a metal ground plate, disposed on the second surface; and a first isolation unit group (120a and 120b), disposed on the first surface, and disposed between adjacent two of the plurality of antenna elements (110a and 110b), wherein an arrangement direction of the first isolation unit group (120a and 120b) is perpendicular to the first polarization direction and the second polarization direction, wherein the first isolation unit group (120a and 120b) is two isolation units (120a and 120b) which are disposed adjacent to each other along a direction perpendicular to the first polarization direction and the second polarization direction, each of the two isolation units (120a and 120b) comprises an outer end and an inner end opposite to the outer end, and the inner end of each one of the two isolation units (120a and 120b) is connected to the metal ground plate via a second via, wherein the inner end of a first one of the two isolation units (120a and 120b) is adjacent to the inner end of a second one of the two isolation units (120a and 120b), the outer end of the first one of the two isolation units (120a and 120b) is the end not adjacent to the second one of the two isolation units (120a, 120b), and the outer end of the second one of the two isolation units is the end not adjacent to the first one of the two isolation units, and wherein each one of the two isolation units (120a and 120b) is composed of a metal strip, and a length of each metal strip in the direction perpendicular to the first polarization direction and the second polarization direction is a quarter wavelength of center frequency of a resonance frequency band of the plurality of antenna elements (110a and 110b). a substrate, comprising a first surface and a second surface; a plurality of antenna elements (110a and 110b), disposed on the first surface, wherein the plurality of antenna elements (110a and 110b) have a first polarization direction and a second polarization direction opposite to the first polarization direction, and the plurality of antenna elements (110a and 110b) have a first via (vial) respectively; a metal ground plate, disposed on the second surface; and a first isolation unit group (120a and 120b), disposed on the first surface, and disposed between adjacent two of the plurality of antenna elements (110a and 110b), wherein an arrangement direction of the first isolation unit group (120a and 120b) is perpendicular to the first polarization direction and the second polarization direction, wherein the first isolation unit group (120a and 120b) is two isolation units (120a and 120b) which are disposed adjacent to each other along a direction perpendicular to the first polarization direction and the second polarization direction, each of the two isolation units (120a and 120b) comprises an outer end and an inner end opposite to the outer end, and the inner end of each one of the two isolation units (120a and 120b) is connected to the metal ground plate via a second via, wherein the inner end of a first one of the two isolation units (120a and 120b) is adjacent to the inner end of a second one of the two isolation units (120a and 120b), the outer end of the first one of the two isolation units (120a and 120b) is the end not adjacent to the second one of the two isolation units (120a, 120b), and the outer end of the second one of the two isolation units is the end not adjacent to the first one of the two isolation units, and wherein each one of the two isolation units (120a and 120b) is composed of a metal strip, and a length of each metal strip in the direction perpendicular to the first polarization direction and the second polarization direction is a quarter wavelength of center frequency of a resonance frequency band of the plurality of antenna elements (110a and 110b).