Dual-band radiation system and antenna array thereof
A radiation system includes a low-frequency radiator having a bowl-shaped structure, a high-frequency radiator arranged inside the bowl-shaped structure of the low-frequency radiator, and a metamaterial reflector arranged below the high-frequency radiator. The metamaterial reflector includes a metasurface arranged below the high-frequency radiator and a solid metal plane arranged below the metasurface.
1. A radiation system, comprising:
a low-frequency radiator having a bowl-shaped structure;
a high-frequency radiator arranged inside the bowl-shaped structure of the low-frequency radiator; and
a metamaterial reflector arranged below the high-frequency radiator and inside the bowl shape structure of the low-frequency radiator and comprising:
a metasurface arranged below the high-frequency radiator; and
a solid metal plane arranged below the metasurface.
2. The radiation system of claim 1 , wherein a distance between the metasurface and a lower surface of the high-frequency radiator is in a range from 0.01Iλ h to 0.15λ h , where λ h is a working wavelength of the high-frequency radiator.
3. The radiation system of claim 1 , wherein a distance between the metasurface and the solid metal plane is smaller than 0.2λ h , where λ h is a working wavelength of the high-frequency radiator.
4. The radiation system of claim 1 , wherein the metamaterial reflector further comprises a dielectric material sandwiched between the metasurface and the solid metal plane.
5. The radiation system of claim 1 , wherein the metasurface is smaller than an aperture size of the low-frequency radiator and larger than an aperture size of the high-frequency radiator.
6. The radiation system of claim 1 , wherein the metasurface comprises a flat plane.
7. The radiation system of claim 1 , wherein the metasurface comprises a curved plane.
8. The radiation system of claim 1 , wherein the metasurface comprises a plurality of metal units arranged in a plane, the metal units each having a size smaller than about 0.25λ h , where λ h is a working wavelength of the high-frequency radiator.
9. The radiation system of claim 8 , wherein at least two neighboring ones of the metal units are separated from each other by an interval.
10. The radiation system of claim 8 , wherein the metal units are arranged in a regular array.
11. The radiation system of claim 8 , wherein the metal units are arranged randomly.
12. The radiation system of claim 8 , wherein at least two of the metal units have different sizes or shapes.
13. The radiation system of claim 8 , wherein each of the metal units has one of a rectangular shape, a circular shape, an L-shape, a spiral shape, or a square frame shape.
14. The radiation system of claim 8 , wherein the metasurface further comprises a dielectric slab, and the metal units are arranged on the dielectric slab.
15. The radiation system of claim 1 , wherein the metasurface comprises a plurality of sub-planes, and each sub-plane comprises a plurality of metal units arranged in a plane, the metal units each having a size smaller than 0.25λ h , where λ h is a working wavelength of the high-frequency radiator.
16. The radiation system of claim 1 , wherein a side length of the solid metal plane is smaller than 0.3λ L , where λ L is a working wavelength of the low-frequency radiator.
17. The radiation system of claim 1 , wherein a radiation plane of the high-frequency radiator is at a same level as or is slightly lower than a radiation plane of the low-frequency radiator.
18. The radiation system of claim 1 , further comprising:
a lower reflector arranged below the low-frequency radiator, the lower reflector comprising a main reflecting board arranged parallel to or approximately parallel to the metamaterial reflector.
19. The radiation system of claim 18 , wherein the lower reflector further comprises at least one auxiliary reflecting board, an angle between the main reflecting board and the at least one auxiliary reflecting board being in a range from 90° to 180°.
20. An antenna array, comprising: at least one dual-band radiation unit and at least one single-band radiation unit arranged alternately; wherein each of the at least one dual-band radiation unit comprises:
a low-frequency radiator having a bowl-shaped structure;
a first high-frequency radiator arranged inside the bowl-shaped structure of the low-frequency radiator; and
a first metamaterial reflector arranged below the first high-frequency radiator and comprising: a first metasurface arranged below the first high-frequency radiator, and a first solid metal plane arranged below the first metasurface;
each of the at least one single-band radiation unit comprises:
a second high-frequency radiator; and
a second metamaterial reflector arranged below the second high-frequency radiator and comprising: a second metasurface arranged below the second high-frequency radiator, and a second solid metal plane arranged below the second metasurface.