Cloaked low band elements for multiband radiating arrays
A multiband antenna, having a reflector, and a first array of first radiating elements having a first operational frequency band, the first radiating elements being a plurality of dipole arms, each dipole arm including a plurality of conductive segments coupled in series by a plurality of inductive elements; and a second array of second radiating elements having a second operational frequency band, wherein the plurality of conductive segments each have a length less than one-half wavelength at the second operational frequency band.
1. A multi-band base station antenna, comprising:
a reflector;
a first array of first frequency band cross-dipole radiating elements mounted on the reflector;
a second array of second frequency band cross-dipole radiating elements mounted on the reflector, where the lowest frequency in the second frequency band exceeds the highest frequency in the first frequency band; and
a plurality of parasitic elements, where a first of the parasitic elements comprises a plurality of conductive segments and a plurality of metallization tracks, where the metallization tracks are narrower than the conductive segments, and each metallization track electrically connects a respective pair of the conductive segments.
2. The multi-band base station antenna of claim 1 , wherein the parasitic elements are aligned to be parallel to a longitudinal dimension of the reflector.
3. The multi-band base station antenna of claim 1 , wherein the parasitic elements are aligned to be perpendicular to a longitudinal dimension of the reflector.
4. The multi-band base station antenna of claim 1 , wherein the metallization tracks and conductive segments are formed on a non-conductive substrate.
5. The multi-band base station antenna of claim 1 , wherein the conductive segments each have a length that is less than one-half a wavelength of a highest frequency in the second frequency band.
6. The multi-band base station antenna of claim 1 , wherein each metallization tracks acts as an inductor in the second frequency band.
7. The multi-band base station antenna of claim 1 , wherein the first of the parasitic elements includes at least three metallization tracks.
8. The multi-band base station antenna of claim 1 , wherein the first of the parasitic elements includes at least five metallization tracks.
9. The multi-band base station antenna of claim 1 , wherein the conductive segments are arranged in a line.
10. A parasitic element for a base station antenna, comprising:
at least four conductive segments; and
at least three metallization tracks,
wherein the metallization tracks are narrower than the conductive segments, and wherein each metallization track electrically connects a respective pair of the conductive segments.
11. The parasitic element of claim 10 , wherein the metallization tracks and conductive segments are formed on a non-conductive substrate.
12. The parasitic element of claim 10 , wherein the parasitic element includes at least four metallization tracks.
13. The parasitic element of claim 10 , wherein the conductive segments are arranged in a line.
14. A parasitic element for a base station antenna, comprising:
at least four conductive segments; and
at least three inductors,
wherein each inductor electrically connects a respective pair of the conductive segments.
15. The parasitic element of claim 14 , wherein the metallization tracks and conductive segments are formed on a non-conductive substrate.
16. The parasitic element of claim 14 , wherein the parasitic element includes at least four metallization tracks.
17. The parasitic element of claim 14 , wherein the conductive segments are arranged in a line.