Antenna arrangement

1. An antenna arrangement for a sensor for plant automation, including for fill level or limit level monitoring, comprising:

a primary radiator configured to emit a radar signal;

a first lens configured to focus the radar signal;

at least one second lens configured to optimize the focused radar signal; and

a high-frequency attenuator disposed in an edge region between the first lens and the second lens,

wherein the high-frequency attenuator is configured to suppress side lobes of the radar signal, and

wherein the second lens is disposed at a distance from the first lens and the primary radiator, such that thermal decoupling of the primary radiator and the first lens from the second lens is provided.

2. The antenna arrangement according to claim 1 ,

wherein the high-frequency attenuator is disposed in an edge region between the first lens and the second lens, such that the high-frequency attenuator decouples the first lens and the primary radiator from the second lens thermally, electrically, or medially.

3. The antenna arrangement according to claim 1 ,

further comprising a housing,

wherein the primary radiator is disposed in the housing, and

wherein the housing is configured to receive or form the first lens.

4. The antenna arrangement according to claim 3 ,

wherein the housing has an opening in which the first lens is disposed, and

wherein the housing is configured to receive further components.

5. The antenna arrangement according to claim 1 , wherein the primary radiator and the first lens are integrally formed.

6. The antenna arrangement according to claim 5 , wherein the primary radiator and the first lens are connected to each other by means of a plastic composite.

7. The antenna arrangement according to claim 6 , wherein the plastic composite has a lower dielectric constant than that of the first lens.

8. The antenna arrangement according to claim 1 , wherein the second lens has a longer focal length than that of the first lens.

9. The antenna arrangement according to claim 1 ,

further comprising a third lens,

wherein the third lens is disposed between the first lens and second lens, and

wherein the third lens is configured to increase the distance between the first lens and the second lens by defocusing.

10. The antenna arrangement according to claim 9 , wherein the third lens is thermally, electrically, and/or medially decoupled from the second lens.

11. The antenna arrangement according to claim 1 , wherein the first lens and the second lens are rotationally symmetrical.

12. The antenna arrangement according to claim 1 , wherein the second lens is configured to withstand temperatures in a range from 100° C. to 250° C.

13. A radar measuring arrangement for plant automation, including for fill level or limit level monitoring, comprising:

a container configured to contain a medium; and

an antenna arrangement according to claim 1 ,

wherein the antenna arrangement is configured to determine a filling level or limit level of the medium in the container.

14. A method for determining a limit or level, comprising:

emitting a radar signal by means of a primary radiator;

focusing the emitted radar signal by means of a first lens;

suppressing side lobes of the focused radar signal by a high-frequency attenuator disposed in an edge region between the first lens and the second lens; and

optimizing the focused radar signal by means of a second lens,

wherein the first lens and the second lens are thermally, decoupled from each other.

15. The antenna arrangement according to claim 1 ,

wherein the second lens is disposed at a distance from the first lens and the primary radiator, such that electrical or medial decoupling of the primary radiator and the first lens from the second lens is provided.