Package structure and antenna device using the same

An antenna device, comprising:

• a first substrate, wherein the first substrate comprises an inner surface and an outer surface opposite the inner surface of the first substrate;
• a second substrate facing the first substrate, wherein the second substrate comprises an inner surface and an outer surface opposite the inner surface of the second substrate;
• a first sealant and a plurality of spacers disposed between the first substrate and the second substrate;
• a remaining space between the first substrate and the second substrate and inside the first sealant;
• a die disposed between the first substrate and the second substrate, wherein a part of the remaining space is disposed between the die and the first substrate;
• a redistribution layer disposed between the die and the inner surface of the second substrate;
• an antenna unit electrically connected to the die via the redistribution layer;
• and
• shielding layers disposed on an inner surface of the first substrate and an inner surface of the second substrate,
• wherein the remaining space is vacant or filled with air or inert gases and the antenna unit is arranged on at least one of the inner surface of the first substrate, the outer surface of the first substrate, the inner surface of the second substrate, and the outer surface of the second substrate.