Antenna and communication system

1. An antenna, comprising a first substrate,

wherein the first substrate comprises:

a first base substrate;

at least one first radiation unit on a side of the first base substrate;

a first electrode layer on a side of the first base substrate away from the at least one first radiation unit; and

at least one second radiation unit on a side of the at least one first radiation unit away from the first electrode layer,

wherein an orthographic projection of each of the at least one second radiation unit on the first base substrate at least partially overlaps an orthographic projection of a corresponding one of the at least one first radiation unit on the first base substrate; and

an orthographic projection of the at least one first radiation unit on the first base substrate is within an orthographic projection of the first electrode layer on the first base substrate,

wherein the antenna further comprises a second electrode layer, which is in a same layer as the at least one first radiation unit, wherein the orthographic projection of the at least one first radiation unit on the first base substrate does not overlap an orthographic projection of the second electrode layer on the first base substrate.

2. The antenna according to claim 1 , wherein

the first base substrate comprises a first side extending in a first direction;

the second electrode layer comprises at least one second sub-electrode;

each of the at least one second sub-electrode is on a side of one of the at least one first radiation unit close to the first side;

each of the at least one second sub-electrode comprises a first structure and a second structure;

the first structure extends along the first direction, and the second structure extends along a second direction; and

the first direction intersects with the second direction.

3. The antenna according to claim 2 , further comprising

a first feeding unit, which is in a same layer as the at least one first radiation unit; wherein

the first feeding unit comprises a plurality of first feeding lines, and

each of the at least one first radiation unit is electrically connected to at least one of the plurality of first feeding lines.

4. The antenna according to claim 3 , wherein

every two of the plurality of first feeding lines are electrically connected to one of the at least one first radiation unit, and

for each of the at least one first radiation unit, one of the at least one second sub-electrode is between the two first feeding lines electrically connected to the first radiation unit, to isolate signals in the two first feeding lines from each other.

5. The antenna according to claim 1 , further comprising

a third electrode layer, which is in a same layer as the at least one second radiation unit, wherein

an orthographic projection of the at least one second radiation unit on the first base substrate does not overlap an orthographic projection of the third electrode layer on the first base substrate.

6. The antenna according to claim 5 , wherein

the first base substrate further comprises a second side extending in a first direction;

an orthographic projection of the third electrode layer on the first base substrate is on a side of the first base substrate close to the second side;

the third electrode layer comprises a main body structure, and a first extension structure and a second extension structure which are connected to both sides of the main body structure, respectively,

the main body structure extends along the first direction, and the first extension structure and the second extension structure both extend along a second direction; and

wherein the first direction and the second direction intersect with each other.

7. The antenna according to claim 1 , further comprising

a first feeding unit, which is in a same layer as the at least one first radiation unit; wherein

the first feeding unit comprises a plurality of first feeding lines, and

every two of the plurality of first feeding lines are electrically connected to one of the at least one first radiation unit.

8. The antenna according to claim 7 , wherein

each of the at least one first radiation unit has a shape of a centrosymmetric pattern having a symmetry center;

for each of the at least one first radiation unit, a position where one of the two first feeding lines is connected to the first radiation unit is a first connecting point, and a position where the other of the two first feeding lines is connected to the first radiation unit is a second connecting point, and

wherein for each of the at least one first radiation unit, an extending direction of a connecting line between the first connecting point and the symmetry center of the first radiation unit intersects with an extending direction of a connecting line between the second connecting point and the symmetry center of the first radiation unit.

9. The antenna according to claim 7 , further comprising a second substrate; wherein

the second substrate comprises a second base substrate and a second feeding unit on a side of the second base substrate and electrically connected to the first feeding unit.

10. The antenna according to claim 9 , wherein

an included angle is between the second substrate and the first substrate.

11. The antenna according to claim 9 , wherein

the second feeding unit comprises a first feeding sub-unit and a second feeding sub-unit, each of the first feeding sub-unit and the second feeding sub-unit comprises one first port and at least one second port; and

for each of the at least one first radiation unit, one of the two first feeding lines electrically connected to the first radiation unit is electrically connected to one of the at least one second port of the first feeding sub-unit, and different first feeding lines are connected to different second ports of the first feeding sub-unit, respectively; and the other of the two first feeding lines electrically connected to the first radiation unit is electrically connected to one of the at least one second port of the second feeding sub-unit, and different first feeding lines are connected to different second ports of the second feeding sub-unit, respectively.

12. The antenna according to claim 1 , further comprising

a third substrate, which is on a side of the first substrate away from the first electrode layer;

wherein the third substrate comprises a third base substrate; and

wherein the at least one second radiation unit is on a side of the third base substrate.

13. The antenna according to claim 1 , further comprising

a fourth substrate, which is on a side of the first substrate away from the at least one first radiation unit;

wherein the fourth substrate comprises a fourth base substrate; and

wherein the first electrode layer is on a side of the fourth base substrate close to the first substrate.

14. The antenna according to claim 1 , wherein

the first substrate further comprises a first metal mesh layer, which is on a side of the first base substrate away from the first electrode layer;

the first metal mesh layer comprises the at least one first radiation unit;

the first metal mesh layer has at least one first cutout therein, and

each of the at least one first cutout separates out one of the at least one first radiation unit.

15. The antenna according to claim 1 , further comprising

a third substrate, which is on a side of the first substrate away from the first electrode layer;

wherein the third substrate comprises a third base substrate and a second metal mesh layer on a side of the third base substrate away from the first base substrate;

the second metal mesh layer comprises the at least one second radiation unit;

the second metal layer has at least one second cutout therein, and

each of the at least one second cutout separates out one of the at least one second radiation unit.

16. The antenna according to claim 1 , wherein

at least one first groove is on a side of the first base substrate away from the at least one first radiation unit, and

an orthographic projection of each of the at least one first groove on the first base substrate covers an orthographic projection of a corresponding one of the at least one first radiation unit on the first base substrate.

17. The antenna according to claim 10 , wherein

the first base substrate is divided by the second base substrate into a first region and a second region along a length direction of the first base substrate; and

a width of the first region in a direction perpendicular to the length direction of the first base substrate is less than a width of the second region in the direction perpendicular to the length direction of the first substrate.

18. The antenna according to claim 17 , further comprising

a third substrate, which is on a side of the first substrate away from the first electrode layer;

wherein the third substrate comprises a third base substrate and a surrounding plate obliquely arranged at an edge of the third base substrate;

wherein the at least one second radiation unit is on a side of the third base substrate away from the at least one first radiation unit;

the antenna further comprises a fourth substrate, which is arranged on a side of the first substrate away from the at least one first radiation unit;

the fourth substrate comprises a fourth base substrate;

wherein the first electrode layer is on a side of the fourth base substrate close to the first substrate; and

the second base substrate, a part of the third base substrate corresponding to the first region, the surrounding plate closest to the second base substrate and a part of the third base substrate corresponding to the first region define an accommodating space.

19. A communication system, comprising an antenna according to claim 1 .