RFID antenna and RFID tag
Provided are a radio frequency identification (RFID) antenna and an RFID tag including the RFID antenna. The RFID antenna includes an electric conductor and a conductor that radiate electromagnetic fields isotropically. The RFID tag including the RFID antenna can be installed on a metal plate.
1. A radio frequency identification antenna comprising:
a closed loop shaped electric conductor to which electric power is supplied; and
an open loop shaped conductor at an outer side of the electric conductor with no electric contact with the electric conductor,
wherein the open low shaped conductor comprises:
a first conductor formed along a line of the electric conductor extending from a feeding point of the electric conductor, and having at least one corner; and
a second conductor electrically opened from the first conductor and formed along a line of the electric conductor distant from the feeding point of the electric conductor.
2. The radio frequency identification antenna according to claim 1 , wherein the electric conductor and the open loop shaped conductor have a polygonal or elliptical shape.
3. The radio frequency identification antenna according to claim 1 , wherein the electric conductor and the open loop shaped conductor are formed on the same plane.
4. The radio frequency identification antenna according to claim 1 , wherein the electric conductor and the open loop shaped conductor have an isotropic radiation pattern by inductive coupling caused by a current supplied to the electric conductor.
5. The radio frequency identification antenna according to claim 1 , wherein the open loop shaped conductor comprises a plurality of conductors electrically opened from each other at side corners distant from a feeding point of the electric conductor.
6. The radio frequency identification antenna according to claim 1 , wherein the electric conductor or the open loop shaped conductor has at least one internal angle ranging from 60° to 320°.
7. A radio frequency identification tag comprising:
an antenna including a closed loop shaped electric conductor to which electric power is supplied and an open loop shaped conductor at an outer side of the electric conductor with no electric contact with the electric conductor; and
a semiconductor chip electrically connected to a feeding point of the electric conductor,
wherein the open loop shaped conductor comprises:
a first conductor formed with a space along an outside of a line of the electric conductor extending from the feeding point, and having, at least one corner; and
a second conductor electrically opened from the first conductor and formed with a space along an outside of a line of electric conductor distant from the feeding point.
8. The radio frequency identification tag according to claim 7 , comprising a base member on which the electric conductor and the open loop shaped conductor are printed into a predetermined pattern at the same side.
9. The radio frequency identification tag according to claim 8 , wherein the base member is formed of a material selected from the group consisting of polyethylene terephthalate (PET), polyimide (PI), polyethylene naphthalate (PEN), polyvinyl chloride (PVC), acetate, polyester, polyethylene, polypropylene, calcium carbonate, plastic, non-conductive material, and a combination thereof.
10. The radio frequency identification tag according to claim 7 , wherein the electric conductor and the open loop shaped conductor are formed into a symmetric or asymmetric polygonal shape, or symmetric or asymmetric elliptical shape.
11. The radio frequency identification tag according to claim 7 , wherein the antenna has an isotropic radiation pattern by inductive coupling between the electric conductor and the open loop shaped conductor caused by a current supplied to the electric conductor.
12. The radio frequency identification tag according to claim 7 , wherein the RFID tag is an active or passive RFID tag operating in an UHF band.