Sidelobe suppression in multi-beam base station antennas
A lensed multi-beam base station antenna may include a plurality of linear arrays of radiating elements, a plurality of reflectors, a sidelobe suppressor, and a lens. Each array may include a plurality of radiating elements (e.g., two or more radiating elements) that extends forwardly from a planar section of a respective reflector. The sidelobe suppressor may comprise radiofrequency (RF) absorber material that absorbs energy that is emitted by a first of the arrays and that is directed toward a reflector underneath a second of the arrays. The sidelobe suppressor may comprise a RF choke that reduces the RF energy emitted by a first of the arrays that is directed toward a reflector underneath a second of the arrays.
1. An antenna comprising:
a housing;
at least one lens mounted within the housing;
a first reflector and a second reflector;
a first array of radiating elements extending forwardly from a front surface of a planar section of the first reflector;
a second array of radiating elements extending forwardly from a front surface of a planar section of the second reflector, wherein a first plane comprising the front surface of the planar section of the first reflector and a second plane comprising the front surface of the planar section of the second reflector intersect at an oblique angle; and
a sidelobe suppressor configured to reduce first radio frequency (RF) energy emitted by the first array of radiating elements and reflected by the second reflector,
wherein the sidelobe suppressor is on first portions of the front surface of the first reflector and/or the front surface of the second reflector, and
wherein second portions of the front surface of the first reflector and/or the front surface of the second reflector below the radiating elements are uncovered by the sidelobe suppressor.
2. The antenna of claim 1 , wherein the sidelobe suppressor comprises a RF absorber material covering a portion of the front surface of the planar section of the second reflector, and wherein the front surface of the planar section of the second reflector faces towards the at least one lens.
3. The antenna of claim 2 , wherein the RF absorber material covers at least 70% of a surface area of the front surface of the planar section of the second reflector.
4. The antenna of claim 2 , wherein the second reflector comprises an outer wall angled with respect to the planar section of the second reflector, wherein the RF absorber material covers an inner surface of the outer wall, and wherein the inner surface faces towards the at least one lens.
5. The antenna of claim 2 , wherein the sidelobe suppressor further comprises a RF absorber material covering a portion of a front surface of the planar section of the first reflector, and wherein the front surface of the planar section of the first reflector faces towards the lens.
6. The antenna of claim 5 , wherein the RF absorber material covers at least 70% of a surface area of the front surface of the first reflector.
7. The antenna of claim 2 , further comprising an inner wall arranged between the planar section of the first reflector and the planar section of the second reflector.
8. The antenna of claim 7 , wherein a RF absorber material at least partially covers a surface of the inner wall facing the first array of radiating elements or the second array of radiating elements.
9. The antenna of claim 7 , wherein a gap exists between the inner wall and an innermost surface of the RF absorber material covering the portion of the front surface of the planar section of the second reflector.
10. The antenna of claim 1 , wherein the sidelobe suppressor comprises a RF choke positioned between the planar section of the first reflector and the planar section of the second reflector.
11. The antenna of claim 10 , wherein the RF choke has a length equal to a length of the first array of radiating elements.
12. The antenna of claim 1 , wherein a unitary component comprises the first reflector and the second reflector.
13. An antenna comprising:
a housing;
at least one lens mounted within the housing;
a first reflector and a second reflector;
a first array of radiating elements mounted to and extending forwardly from a front surface of a planar section of the first reflector;
a second array of radiating elements extending forwardly from a front surface of a planar section of the second reflector, wherein a first plane comprising the front surface of the planar section of the first reflector and a second plane comprising the front surface of the planar section of the second reflector intersect at an oblique angle; and
radio frequency (RF) absorber material covering a portion of the front surface of the planar section of the first reflector and a portion of the front surface of the planar section of the second reflector, wherein the front surfaces of the planar sections of the first and second reflectors face toward the at least one lens, and wherein the RF absorber material is configured to absorb first RF energy emitted by the first array of radiating elements that is directed toward the second reflector and is configured to absorb second RF energy emitted by the second array of radiating elements that is directed toward the first reflector.
14. The antenna of claim 13 , further comprising an inner wall positioned between the first reflector and the second reflector.
15. The antenna of claim 14 , wherein the first reflector comprises an outer wall angled with respect to the planar section of the first reflector, wherein the second reflector comprises an outer wall angled with respect to the planar section of the second reflector, and wherein the outer wall of the first reflector and the outer wall of the second reflector extend in parallel to each other.
16. The antenna of claim 15 , wherein the RF absorber material covers a portion of an inner surface of the outer wall of the first reflector and covers a portion of an inner surface of the outer wall of the second reflector, wherein the inner surface of the outer wall of the first reflector faces toward the at least one lens, and wherein the inner surface of the outer wall of the second reflector faces toward the at least one lens.
17. The antenna of claim 15 , wherein the front surface of the planar section of the first reflector is completely covered by the RF absorber material along a distance from the inner wall to the outer wall of the first reflector.
18. The antenna of claim 14 , wherein a portion of the front surface of the planar section of the first reflector that is proximate to the inner wall is uncovered by the RF absorber material.
19. An antenna comprising:
at least one lens mounted within a housing;
a first reflector and a second reflector;
a first array of radiating elements extending forwardly from a front surface of a planar section of the first reflector;
a second array of radiating elements extending forwardly from a front surface of a planar section of the second reflector, wherein a first plane comprising the front surface of the planar section of the first reflector and a second plane comprising the front surface of the planar section of the second reflector intersect at an oblique angle; and
a radio frequency (RF) choke positioned between the planar section of the first reflector and the planar section of the second reflector;
wherein the RF choke is configured to reduce first RF energy emitted by the first array of radiating elements that is directed toward the second reflector and reduce second RF energy emitted by the second array of radiating elements that is directed toward the first reflector.
20. The antenna of claim 19 , wherein the first reflector, second reflector, and RF choke are formed as a unitary component.