Wideband radiating elements including parasitic elements and related base station antennas
A radiating element for a base station antenna includes a first dipole radiator that has a first dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the first dipole arm; a second dipole radiator that has a second dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the second dipole arm; and a parasitic element having a first conductive segment that is configured to capacitively couple to the first extension of the first dipole arm, a second conductive segment that is configured to capacitively couple to the second extension of the second dipole arm, and a third conductive segment that electrically connects the first conductive segment to the second conductive segment.
1. A radiating element for a base station antenna, comprising
a first dipole radiator that includes a first dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the first dipole arm;
a second dipole radiator that includes a second dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the second dipole arm; and
a parasitic element having a first conductive segment that is configured to capacitively couple to the first extension of the first dipole arm, a second conductive segment that is configured to capacitively couple to the second extension of the second dipole arm, and a third conductive segment that electrically connects the first conductive segment to the second conductive segment,
wherein the parasitic element fits within a physical footprint of the radiating element.
2. The radiating element of claim 1 , wherein the first conductive segment is positioned adjacent a rear edge of the first extension of the first dipole arm, and the second conductive segment is positioned adjacent a rear edge of the second extension of the second dipole arm.
3. The radiating element of claim 1 , wherein the first conductive segment, the second conductive segment and the third conductive segment of the parasitic element are all positioned between the first dipole arm and the second dipole arm.
4. The radiating element of claim 1 , wherein the first dipole radiator further includes a third dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the third dipole arm, and the second dipole radiator further includes a fourth dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the fourth dipole arm.
5. The radiating element of claim 4 , wherein the first dipole arm further includes a third extension that projects rearwardly from a distal end of the front surface of the first dipole arm, and wherein the fourth dipole arm further includes a third extension that projects rearwardly from a distal end of the front surface of the fourth dipole arm.
6. The radiating element of claim 4 , wherein the first dipole arm further includes a third extension that projects rearwardly from a distal end of the front surface of the first dipole arm, and wherein the second dipole arm does not include an extension that projects rearwardly from a distal end of the front surface of the second dipole arm.
7. The radiating element of claim 1 , wherein the parasitic element is configured so that when the first dipole arm is excited, current flows outwardly on the first dipole arm and current flows inwardly on the first conductive segment.
8. The radiating element of claim 1 , wherein each of the first conductive segment, the second conductive segment and the third conductive segment of the parasitic element is an elongated element having a length, a width and a depth, where the length exceeds the width and the depth by at least a factor of ten.
9. The radiating element of claim 4 , wherein the radiating element further comprises:
a second parasitic element having a first conductive segment that is configured to capacitively couple to the first extension of the second dipole arm, a second conductive segment that is configured to capacitively couple to the second extension of the third dipole arm, and a third conductive segment that electrically connects the first conductive segment of the second parasitic element to the second conductive segment of the second parasitic element;
a third parasitic element having a first conductive segment that is configured to capacitively couple to the first extension of the third dipole arm, a second conductive segment that is configured to capacitively couple to the second extension of the fourth dipole arm, and a third conductive segment that electrically connects the first conductive segment of the third parasitic element to the second conductive segment of the third parasitic element; and
a fourth parasitic element having a first conductive segment that is configured to capacitively couple to the first extension of the fourth dipole arm, a second conductive segment that is configured to capacitively couple to the second extension of the first dipole arm, and a third conductive segment that electrically connects the first conductive segment of the fourth parasitic element to the second conductive segment of the fourth parasitic element.
10. A radiating element for a base station antenna, comprising
a first dipole radiator that includes a first dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the first dipole arm;
a second dipole radiator that includes a second dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the second dipole arm; and
a parasitic element having a first conductive segment that is configured to capacitively couple to the first extension of the first dipole arm, a second conductive segment that is configured to capacitively couple to the second extension of the second dipole arm, and a third conductive segment that electrically connects the first conductive segment to the second conductive segment,
wherein a first end of the first conductive segment is adjacent a base of the first dipole arm and a second end of the first conductive segment is adjacent a distal end of the first dipole arm.
11. The radiating element of claim 10 , wherein the parasitic element is completely positioned within a smallest square that fits around the first and second dipole radiators when the radiating element is viewed from the front.
12. The radiating element of claim 10 , wherein the first conductive segment is positioned adjacent a rear edge of the first extension of the first dipole arm, and the second conductive segment is positioned adjacent a rear edge of the second extension of the second dipole arm.
13. The radiating element of claim 10 , wherein the first dipole arm further includes a third extension that projects rearwardly from a distal end of the front surface of the first dipole arm, and wherein the second dipole arm does not include an extension that projects rearwardly from a distal end of the front surface of the second dipole arm.
14. The radiating element of claim 10 , wherein the parasitic element is configured so that when the first dipole arm is excited, current flows outwardly on the first dipole arm and current flows inwardly on the first conductive segment.
15. The radiating element of claim 10 , wherein the parasitic element is configured to increase a length of a current path for radio frequency (“RF”) energy in a lower portion of an operating frequency band of the radiating element and to provide less of an increase in a current path for RF energy in an upper portion of the operating frequency band of the radiating element.
16. A new radiating element for a base station antenna, comprising
a first dipole radiator that includes a first dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the first dipole arm;
a second dipole radiator that includes a second dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the second dipole arm; and
a parasitic element having a first conductive segment that is configured to capacitively couple to the first extension of the first dipole arm, a second conductive segment that is configured to capacitively couple to the second extension of the second dipole arm, and a third conductive segment that electrically connects the first conductive segment to the second conductive segment,
wherein the first and second dipole radiators and the parasitic element are configured so that a first percentage of radio frequency (“RF”) energy in a lower portion of an operating frequency band of the radiating element passes from the first and second dipole radiators to the parasitic element, and a second percentage of RF energy in an upper portion of the operating frequency band of the radiating element passes from the first and second dipole radiators to the parasitic element, wherein the first percentage is greater than the second percentage,
wherein the first conductive segment, the second conductive segment and the third conductive segment of the parasitic element are all positioned between the first dipole arm and the second dipole arm.
17. The radiating element of claim 16 , wherein the parasitic element fits within a physical footprint of the first and second dipole radiators.
18. The radiating element of claim 16 , wherein the first dipole arm further includes a third extension that projects rearwardly from a distal end of the front surface of the first dipole arm, and wherein the second dipole arm does not include an extension that projects rearwardly from a distal end of the front surface of the second dipole arm.
19. The radiating element of claim 16 , wherein the parasitic element is configured so that when the first dipole arm is excited, current flows outwardly on the first dipole arm and current flows inwardly on the first conductive segment.
20. The radiating element of claim 16 , wherein a first end of the first conductive segment is adjacent a base of the first dipole arm and a second end of the first conductive segment is adjacent a distal end of the first dipole arm.
21. A radiating element for a base station antenna, comprising
a first dipole radiator that includes a first dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the first dipole arm;
a second dipole radiator that includes a second dipole arm that has a front surface and first and second extensions that project rearwardly from respective side edges of the front surface of the second dipole arm; and
a parasitic element having a first conductive segment that is configured to capacitively couple to the first extension of the first dipole arm, a second conductive segment that is configured to capacitively couple to the second extension of the second dipole arm, and a third conductive segment that electrically connects the first conductive segment to the second conductive segment,
wherein the parasitic element is configured to increase a length of a current path for radio frequency (“RF”) energy in a lower portion of an operating frequency band of the radiating element and to provide less of an increase in a current path for RF energy in an upper portion of the operating frequency band of the radiating element,
wherein the first dipole arm further includes a third extension that projects rearwardly from a distal end of the front surface of the first dipole arm, and wherein the second dipole arm does not include an extension that projects rearwardly from a distal end of the front surface of the second dipole arm.