Antenna device

An antenna device for receiving and transmitting a radio wave at a first frequency and a second frequency, the second frequency higher than the first frequency, the antenna device comprising:

• a ground plate , wherein the ground plate is a first planar conductive member;
• a patch section, wherein the patch section is a second planar conductive member and disposed at a preset distance from and parallel to the ground plate, the patch section having an edge part and a centrally disposed patch center point;
• a plurality of first conductive elements configured to electrically connect the patch section and the ground plate, the plurality of first conductive elements spaced at an equal distance from each other and arranged in a first circle with a first radius from the patch center point;
• a plurality of second conductive elements configured to electrically connect the patch section and the ground plate, the plurality of second conductive elements spaced at an equal distance from each other and arranged in a second circle with a second radius from the patch center point;
• and
• a plurality of capacitive elements of a preset capacitance disposed on an electric current path from the patch section to the ground plate, wherein the second radius is greater than the first radius.