Ultra-wideband omnidirectional and polarization insensitive Duo Aloe Vera Cruces Concentricis antenna structure applied to electromagnetic wave energy absorber, thermoelectric energy harvester, photoconductive antenna, array antenna and rectenna

A thermoelectric energy harvester, comprising:

• a first conductive layer receiving a heat radiation, and comprising:
• a plurality of first metal units arranged around each other to form a first tapered hole;
• and
• a plurality of second metal units located in the first tapered hole and arranged around each other to form a second tapered hole;
• a dielectric layer connected to the first conductive layer;
• a second conductive layer connected to the dielectric layer, wherein the dielectric layer is located between the first conductive layer and the second conductive layer;
• a contact electrode disposed through the dielectric layer and electrically connected between the first conductive layer and the second conductive layer;
• and
• a coaxial cable electrically connected to the contact electrode and converting the heat radiation into a direct current according to a Seebeck effect;
• wherein the first tapered hole has at least one first center line passed through a center of the first tapered hole, the second tapered hole has at least one second center line passed through a center of the second tapered hole, and an included angle between the at least one first center line and the at least one second center line is 45 degrees.