Antenna and fabricating method thereof, and antenna device and fabricating method thereof

1. An antenna, comprising:

a first substrate;

a base material layer on the first substrate and having a plurality of antenna cavities arranged in an array therein; and

a conductive layer on a sidewall of each of the plurality of antenna cavities, each of the plurality of antenna cavities and the conductive layer on the sidewall thereof forming an antenna unit, wherein

each of the plurality of antenna cavities comprises a first opening, and an aperture of the first opening at a position of the antenna cavity close to the first substrate is smaller than an aperture of the first opening at a position of the antenna cavity away from the first substrate, wherein

each of the plurality of antenna cavities comprises a first cavity and a second cavity in physical contact with the first cavity, the second cavity being closer to the first substrate than the first cavity;

the first cavity comprises a second opening, and the second cavity comprises a third opening;

in a direction pointing from the second cavity to the first cavity, an aperture of the second opening gradually increases, and an aperture of the third opening is constant; and

a difference between the aperture of the second opening at a position of the first cavity in physical contact with the second cavity and the aperture of the third opening is smaller than a first value.

2. The antenna of claim 1 , wherein the first value is 1 μm.

3. The antenna of claim 2 , wherein the aperture of the second opening at the position of the first cavity in physical contact with the second cavity is equal to the aperture of the third opening.

4. The antenna of claim 1 , wherein the first cavity comprises at least one first sidewall inclined relative to the first substrate; and the second cavity comprises at least one second sidewall perpendicular to the first substrate.

5. The antenna of claim 4 , wherein the first cavity has a hollow portion of a truncated pyramid shape and comprises four first sidewalls inclined relative to the first substrate; and the second cavity has a hollow portion of a cuboid shape and comprises four second sidewalls perpendicular to the first substrate.

6. The antenna of claim 4 , wherein the first cavity has a hollow portion of a circular truncated cone shape and comprises an arc-shaped first sidewall inclined relative to the first substrate; and the second cavity has a hollow portion of a cylinder shape and comprises an arc-shaped second sidewall perpendicular to the first substrate.

7. The antenna of claim 1 , wherein a material of the base material layer comprises any one of silicon, quartz, and ceramic.

8. An antenna device, comprising the antenna of claim 1 and a phase shifter connected to the antenna.

9. The antenna device of claim 8 , wherein the phase shifter comprises second and third substrates opposite to each other, and a dielectric layer between the second and third substrates, and the second and third substrates are configured to generate an electric field therebetween to change a dielectric constant of the dielectric layer.

10. The antenna device of claim 9 , wherein the first substrate serves as the second substrate.

11. The antenna device of claim 9 , wherein a first electrode layer is on a side of the second substrate close to the third substrate, and a second electrode layer is on a side of the third substrate close to the second substrate;

the first electrode layer has a plurality of slits, the plurality of slits are in one-to-one correspondence with the plurality of antenna cavities, and an orthographic projection of the first opening of each of the plurality of antenna cavities on the third substrate at least partially overlaps with an orthographic projection of the slit corresponding to the first opening on the third substrate; and

the second electrode layer comprises a plurality of sub-electrodes, the plurality of sub-electrodes are in one-to-one correspondence with the plurality of antenna cavities, and the orthographic projection of the first opening of each of the plurality of antenna cavities on the third substrate at least partially overlaps with an orthographic projection of the sub-electrode corresponding to the first opening on the third substrate.

12. The antenna device of claim 11 , wherein each of the plurality of sub-electrodes has a shape of at least one of a comb shape and a spiral shape when viewed in a plan view.

13. A method for fabricating an antenna, comprising:

preparing a first substrate;

forming a base material layer on the first substrate;

forming a plurality of antenna cavities arranged in an array in the base material layer; and

forming a conductive layer on a sidewall of each of the plurality of antenna cavities,

wherein each of the plurality of antenna cavities comprises a first opening, and an aperture of the first opening at a position of the antenna cavity close to the first substrate is smaller than an aperture of the first opening at a position of the antenna cavity away from the first substrate, wherein

each of the plurality of antenna cavities comprises a first cavity and a second cavity in physical contact with the first cavity, the second cavity being closer to the first substrate than the first cavity;

the first cavity comprises a second opening, and the second cavity comprises a third opening;

in a direction pointing from the second cavity to the first cavity, an aperture of the second opening gradually increases, and an aperture of the third opening is constant; and

a difference between the aperture of the second opening at a position of the first cavity in physical contact with the second cavity and the aperture of the third opening is smaller than a first value.

14. The method of claim 13 , wherein a material of the base material layer is silicon; and

forming the plurality of antenna cavities arranged in an array in the base material layer comprises:

forming the plurality of antenna cavities arranged in an array by a bulk silicon etching process.

15. A method for fabricating an antenna device, comprising:

fabricating an antenna, wherein the antenna is the antenna of claim 1 ;

fabricating a phase shifter; and

assembling the antenna and the phase shifter into a single body by a bonding process or a laminating process.

16. The method of claim 15 , wherein

the phase shifter comprises second and third substrates opposite to each other, and a dielectric layer between the second and third substrates, and the second and third substrates are configured to generate an electric field therebetween to change a dielectric constant of the dielectric layer.

17. The method of claim 16 , wherein the first substrate serves as the second substrate.

18. The method of claim 17 , wherein a first electrode layer is on a side of the second substrate close to the third substrate, and a second electrode layer is on a side of the third substrate close to the second substrate;

the first electrode layer has a plurality of slits, the plurality of slits are in one-to-one correspondence with the plurality of antenna cavities, and an orthographic projection of the first opening of each of the plurality of antenna cavities on the third substrate at least partially overlaps with an orthographic projection of the slit corresponding to the first opening on the third substrate; and

the second electrode layer comprises a plurality of sub-electrodes, the plurality of sub-electrodes are in one-to-one correspondence with the plurality of antenna cavities, and the orthographic projection of the first opening of each of the plurality of antenna cavities on the third substrate at least partially overlaps with an orthographic projection of the sub-electrode corresponding to the first opening on the third substrate.

19. The method of claim 18 , wherein each of the plurality of sub-electrodes has a shape of at least one of a comb shape and a spiral shape when viewed in a plan view.