Antenna system having electromagnetic bandgap

1. An antenna system comprising:

an antenna transmitting and receiving a signal;

a power feeding line feeding electric power to the antenna;

a metal conductor ground electrically connected to the power feeding line; and

an electromagnetic bandgap attached to the metal conductor ground,

wherein:

the electromagnetic bandgap has a first surface facing the metal conductor ground and a second surface opposite to the first surface; and

the antenna is disposed above the second surface of the electromagnetic bandgap and is spaced apart from the second surface of the electromagnetic bandgap.

2. The antenna system of claim 1 , wherein the antenna comprises one of a base station antenna and a repeater antenna.

3. The antenna system of claim 2 , wherein the one of the base station antenna and the repeater antenna comprises a reflector reflecting a signal radiated from the antenna, wherein the reflector includes the electromagnetic bandgap.

4. The antenna system of claims 3 , wherein the electromagnetic bandgap is formed by arranging unit cells.

5. The antenna system of claim 2 , wherein the base station antenna comprises one of a monopole antenna, a dipole antenna and a patch antenna.

6. The antenna system of claim 1 , wherein the antenna comprises a satellite-tracking antenna.

7. The antenna system of claim 6 , wherein the satellite-tracking antenna comprises one of a film slot antenna and a waveguide slot antenna.

8. The antenna system of claim 1 , wherein the antenna comprises a vehicle antenna.

9. The antenna system of claim 8 , wherein the vehicle antenna comprises one of a monopole antenna and a glass antenna.

10. The antenna system of claims 1 , wherein the electromagnetic bandgap is formed by arranging unit cells.

11. The antenna system of claim 10 , wherein each of the unit cells comprises:

a dielectric formed on the metal conductor ground; and

a cell pattern of the electromagnetic bandgap formed on the dielectric.

12. The antenna system of claim 11 , wherein the unit cells of the electromagnetic bandgap are periodically arranged to neighbor each other with a preset interval therebetween and to form an overall cell pattern of the electromagnetic bandgap.

13. The antenna system of claim 11 , wherein each of the unit cells further comprises a via-hole penetrating through the dielectric and formed between the metal conductor ground and the unit cells of the electromagnetic bandgap.

14. The antenna system of claim 1 , wherein the power feeding line includes a first portion facing the second surface of the electromagnetic bandgap and a second portion opposite to the first portion, and the antenna extends from second portion of the power feeding line in a direction to be spaced gradually further apart from the second portion of the power feeding line.

15. The antenna system of claim 1 , wherein the power feeding line includes a power feeding patch that has a first surface facing the second surface of the electromagnetic bandgap and a second surface opposite to the first surface, and the antenna is disposed to face and be spaced apart from the second surface of the power feeding patch.

16. The antenna system of claim 15 , wherein the power feeding patch includes a power feeding point and a power distribution circuit.