Reflector structure and antenna device

An antenna device, comprising:

• an antenna structure having at least one excitation source;
• and
• a reflector structure configured to reflect a radiation of the antenna structure, wherein the reflector structure comprises:
• a metal substrate having a virtual normal;
• at least one first flat plate disposed on the metal substrate;
• and
• a second flat plate floated to the metal substrate along the virtual normal and completely separated from the at least one first plate to form a closed slot;
• wherein a cavity is formed by the metal substrate, the at least one first flat plate and the second flat plate, and the cavity is communicated with the closed slot;
• wherein the closed slot is located on a plane, the at least one excitation source is projected onto the plane to form an excitation source region, and the excitation source region is located in the second flat plate.