Base station antenna feed boards having RF transmission lines of different types for providing different transmission speeds
Base station antenna feed boards are provided. A base station antenna feed board includes a phase shifter and a hybrid radio frequency transmission line that is coupled to the phase shifter. The hybrid radio frequency transmission line includes a coplanar waveguide and a microstrip line. Related base station antennas are also provided.
1. A base station antenna comprising:
a printed circuit board (PCB) comprising a phase shifter and a plurality of radio frequency (RF) transmission lines that are coupled to the phase shifter; and
a plurality of radiating elements that are on the PCB and coupled to the RF transmission lines,
wherein a first of the RF transmission lines comprises a coplanar waveguide (CPW) that is coupled between a first of the radiating elements and the phase shifter,
wherein a second of the radiating elements is coupled to a second of the RF transmission lines that is shorter in length than a length of the first of the RF transmission lines, wherein the second of the RF transmission lines is coupled between the second of the radiating elements and the phase shifter, and
wherein the second of the RF transmission lines is free of any CPW.
2. The base station antenna of claim 1 , wherein the first of the radiating elements is located farther from the phase shifter than the second of the radiating elements from the phase shifter.
3. The base station antenna of claim 1 , wherein the second of the RF transmission lines comprises a microstrip line.
4. The base station antenna of claim 1 , wherein the first of the RF transmission lines further comprises at least one microstrip line.
5. The base station antenna of claim 4 , wherein the at least one microstrip line comprises:
a first microstrip line that couples the CPW to the phase shifter; and
a second microstrip line that couples the CPW to the first of the radiating elements.
6. The base station antenna of claim 1 , wherein the CPW comprises:
three coplanar conductive lines on a first surface of the PCB; and
grounded vias that couple two of the coplanar conductive lines to a ground plane that is on a second surface of the PCB that is opposite the first surface.
7. The base station antenna of claim 6 ,
wherein first and second rows of the grounded vias are on first and second portions, respectively, of the ground plane, and
wherein the ground plane comprises an opening therein that is between the first and second portions of the ground plane.
8. The base station antenna of claim 6 , wherein the three coplanar conductive lines comprise first, second, and third coplanar conductive lines, wherein the first and third coplanar conductive lines are the two of the coplanar conductive lines that are coupled to the ground plane by the grounded vias, and wherein the second coplanar conductive line is between the first and third coplanar conductive lines, the base station antenna further comprising:
a reflector that faces the ground plane,
wherein the reflector comprises an opening therein that is overlapped by the second coplanar conductive line.
9. The base station antenna of claim 1 ,
wherein the CPW comprises a first of a plurality of CPWs of the PCB, and
wherein the phase shifter comprises a first of a plurality of phase shifters of the PCB that are coupled to the CPWs, respectively.
10. The base station antenna of claim 1 , wherein the CPW is further coupled to a third of the radiating elements.
11. The base station antenna of claim 10 , wherein the second of the RF transmission lines is further coupled to a fourth of the radiating elements.
12. A base station antenna comprising:
a reflector comprising an opening therein;
a printed circuit board (PCB) on the reflector and comprising a phase shifter and a plurality of radio frequency (RF) transmission lines that are coupled to the phase shifter; and
a plurality of radiating elements that are on the PCB and coupled to the plurality of RF transmission lines,
wherein a first of the plurality of RF transmission lines is coupled to a first of the plurality of radiating elements and comprises a coplanar waveguide (CPW) that overlaps the opening of the reflector.
13. The base station antenna of claim 12 , wherein the first of the RF transmission lines further comprises a microstrip line that is coupled to the CPW.
14. The base station antenna of claim 13 , wherein the CPW is coupled to the phase shifter by the microstrip line.
15. The base station antenna of claim 13 , wherein the CPW is coupled to the first of the radiating elements by the microstrip line.
16. The base station antenna of claim 13 ,
wherein the microstrip line comprises a first of a pair of microstrip lines of the first of the RF transmission lines, and
wherein the CPW is coupled between the pair of microstrip lines.
17. A base station antenna feed board comprising:
a phase shifter;
first and second radiating elements;
a hybrid radio frequency (RF) transmission line that is coupled to the phase shifter and includes a coplanar waveguide (CPW) and a microstrip line, wherein the hybrid RF transmission line is coupled between the phase shifter and the first radiating element; and
a non-CPW RF transmission line that is coupled between the phase shifter and the second radiating element,
wherein a length of the hybrid RF transmission line between the phase shifter and the first radiating element is longer than a length of the non-CPW RF transmission line between the phase shifter and the second radiating element of the base station antenna feed board.
18. The base station antenna feed board of claim 17 , wherein the microstrip line is a first microstrip line coupled between the CPW and the phase shifter, and wherein the hybrid RF transmission line further comprises a second microstrip line coupled between the CPW and the first radiating element.
19. The base station antenna feed board of claim 17 , wherein the CPW comprises:
two outer conductive lines on a first surface of the base station antenna feed board;
a center conductive line that is coupled to the microstrip line and is between the two outer conductive lines on the first surface of the base station antenna feed board; and
grounded vias that couple the two outer conductive lines to a ground plane that is on a second surface of the base station antenna feed board that is opposite the first surface.
20. The base station antenna feed board of claim 19 , further comprising:
a second-layer conductive line that is on the second surface of the base station antenna feed board and is overlapped by the center conductive line; and
ungrounded vias that couple the center conductive line and the second-layer conductive line to each other,
wherein the ground plane comprises first and second portions that are overlapped by the two outer conductive lines, respectively, and
wherein the ground plane further comprises an opening that separates the second-layer conductive line from the first and second portions of the ground plane.
21. A base station antenna feed board comprising:
a phase shifter;
first and second radiating elements; and
first and second radio frequency (RF) transmission lines that are coupled to the phase shifter and configured to have first and second RF wave speeds, respectively, wherein the second RF wave speed is slower than the first RF wave speed, wherein the first RF transmission line is coupled between the phase shifter and the first radiating element, and wherein the second RF transmission line is coupled between the phase shifter and the second radiating element
wherein the first RF transmission line comprises a coplanar waveguide (CPW), and
wherein the second RF transmission line is a non-CPW RF transmission line.
22. The base station antenna feed board of claim 21 , wherein the first RF transmission line comprises a coaxial RF transmission line having a shield and a center conductor that is separated from the shield by air.
23. The base station antenna feed board of claim 21 , wherein the first RF transmission line comprises a conductive line that is separated from a ground plane of the base station antenna feed board by air.
24. The base station antenna feed board of claim 21 , wherein the first RF transmission line is longer in length between the phase shifter and the first radiating element than a length of the second RF transmission line between the phase shifter and the second radiating element.
25. The base station antenna feed board of claim 23 , further comprising:
a reflector, wherein a substrate of the base station antenna feed board is between the ground plane and the reflector.