Liquid crystal antenna and its manufacturing method

1. A liquid crystal antenna, comprising: a first substrate, a second substrate, and liquid crystals arranged between the first substrate and the second substrate, wherein first protrusions and second protrusions are arranged at a surface of the second substrate facing the first substrate, a size of each first protrusion in a first direction is substantially greater than a size of each second protrusion in the first direction, and the first direction is a direction perpendicularly from the second substrate to the first substrate, and wherein a run-through labyrinth-type gap is defined by the first protrusions at a surface of the second substrate, and each second protrusion is arranged in the labyrinth-type gap,

wherein a metallic shielding layer is arranged at an outer surface of each first protrusion.

2. The liquid crystal antenna according to claim 1 , wherein the run-through labyrinth-type gap refers to a plurality of consecutive zigzag gaps at the surface of the second substrate.

3. The liquid crystal antenna according to claim 1 , wherein each second protrusion is arranged in the middle of the labyrinth-type gap to divide the labyrinth-type gap into two even parts.

4. The liquid crystal antenna according to claim 1 , wherein the run-through labyrinth-type gap is a labyrinth of a specific shape defined by the first protrusions as walls and having interconnected spaces rather than any independent closed region, so as to allow the liquid crystals to flow between the first substrate and the second substrate.

5. The liquid crystal antenna according to claim 1 , wherein an electrode layer covers a surface of the first substrate facing the second substrate.

6. The liquid crystal antenna according to claim 5 , wherein a delay line layer covers an outer surface of each second protrusion and is arranged substantially parallel to the electrode layer.

7. The liquid crystal antenna according to claim 6 , wherein the first substrate is provided with a groove having an isosceles-trapezoid-like cross section, and an orthogonal projection of the delay line layer onto the first substrate falls within the groove.

8. The liquid crystal antenna according to claim 6 , wherein a cross section of the delay line layer in the first direction is of an arc-like shape.

9. The liquid crystal antenna according to claim 6 , wherein a cross section of the delay line layer in the first direction is of an isosceles-trapezoid-like shape.

10. The liquid crystal antenna according to claim 5 , wherein an insulation layer is arranged on the first substrate, and the electrode layer is arranged at a surface of the insulation layer facing the second substrate.

11. The liquid crystal antenna according to claim 10 , wherein the size of each first protrusion in the first direction is substantially equal to a maximum size of the insulation layer in the first direction, and a ratio of the size of each second protrusion to the size of each first protrusion in the first direction is not greater than ½.

12. The liquid crystal antenna according to claim 1 , wherein one or more support members is uniformly arranged between an upper end surface of the metallic shielding layer and the first substrate.

13. The liquid crystal antenna according to claim 12 , wherein the first protrusions, the second protrusions and the support members are each made of polystyrene.

14. The liquid crystal antenna according to claim 12 , wherein each support member is of a spherical shape, and a diameter of the support member is smaller than a thickness of the first protrusion.

15. The liquid crystal antenna according to claim 1 , wherein a snake-like gap is defined by the first protrusions at the surface of the second substrate, and each second protrusion is arranged in a snake-like form in the snake-like gap.