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 cross dipole radiating element, comprising:
a first dipole arm that comprises a plurality of first conductive segments and a plurality of first metallization tracks that are each on a first non-conductive substrate, where the first metallization tracks are narrower than the first conductive segments, each first metallization track electrically connecting a respective pair of the first conductive segments.
2. The cross dipole radiating element of claim 1 , further comprising a second dipole arm that comprises a plurality of second conductive segments and a plurality of second metallization tracks that are each on a second non-conductive substrate, where the second metallization tracks are narrower than the second conductive segments, each second metallization track electrically connecting a respective pair of the second conductive segments.
3. The cross dipole radiating element of claim 2 , further comprising a third dipole arm and a fourth dipole arm, wherein the first dipole arm and the third dipole arm comprise a first dipole radiator and the second dipole arm and the fourth dipole arm comprise a second dipole radiator.
4. The cross dipole radiating element of claim 1 , wherein the first metallization tracks comprise meandered metallization tracks.
5. The cross dipole radiating element of claim 1 , wherein the first metallization tracks comprise U-shaped metallization tracks.
6. The cross dipole radiating element of claim 1 , wherein the first metallization tracks comprise respective inductive elements.
7. A base station antenna that comprises:
the cross dipole radiating element of claim 1 ; and
a second radiating element,
wherein the cross dipole radiating element of claim 1 is configured to operate in a first frequency band and the second radiating element is configured to operate in a second frequency band that includes a frequency that is twice a frequency in the first frequency band.
8. The base station antenna of claim 7 , wherein the first conductive segments each have a length that is less than one-half a wavelength of a highest frequency in the second frequency band.
9. The cross dipole radiating element of claim 8 , wherein the first metallization tracks have an impedance that acts to attenuate currents in the second frequency band.
10. The cross dipole radiating element of claim 8 , wherein the cross dipole radiating element is electrically invisible in the second frequency band.
11. The base station antenna of claim 7 , wherein the first frequency band is the 694-960 MHz frequency band.
12. The base station antenna of claim 11 , wherein the second frequency band is the 1695-2690 MHz frequency band.
13. The cross dipole radiating element of claim 1 , wherein the plurality of first conductive segments comprises at least four conductive segments.
14. A cross dipole radiating element, comprising:
a first dipole arm that comprises a first metallization pattern on a first non-conductive substrate, the first metallization pattern including a plurality of first conductive segments and a plurality of U-shaped first metallization tracks.
15. The cross dipole radiating element of claim 14 , wherein each U-shaped first metallization track electrically connects a respective pair of the first conductive segments.
16. The cross dipole radiating element of claim 14 , wherein widths of the U-shaped first metallization tracks are narrower than widths of the first conductive segments.
17. The cross dipole radiating element of claim 14 , further comprising a second dipole arm that comprises a second metallization pattern on a second non-conductive substrate, the second metallization pattern including a plurality of spaced-apart second conductive segments and a plurality of U-shaped second metallization tracks, each U-shaped second metallization track electrically connecting a respective pair of the second conductive segments.
18. A base station antenna, comprising:
a driven radiating element; and
a passive parasitic element comprising a plurality of spaced-apart conductive segments that are electrically connected in series by a plurality of U-shaped metallization tracks.
19. The base station antenna of claim 18 , wherein a number of metallization tracks included in the parasitic element is one less than a number of conductive segments included in the parasitic element.
20. The base station antenna of claim 18 , wherein the conductive segments are arranged in a line.