Enhanced phase shifter circuit to reduce RF cables
A multi-band antenna system includes an array of wide-band radiating elements and a multi-band electrical tilt circuit. The multi-band electrical tilt circuit includes a plurality of combiners, a first RF band variable phase shifter and a second RF band variable phase shifter implemented in a common medium. The common medium may comprise a PCB, a stripline circuit, or the like. Each combiner includes a combined port, a first RF band port, and a second RF band port. The combined ports are coupled to the radiating elements. The first RF band phase shifter has a first plurality of variably phase shifted ports connected to the first RF band ports of the combiners via transmission line, and the second RF band phase shifter has a second plurality of variably phase-shifted ports connected to the second RF band ports of the combiners via transmission line. The phase shifters are independently configurable.
1. A printed circuit board for a multi-band antenna system, the printed circuit board comprising:
a plurality of first radio frequency (“RF”) transmission lines, at least some of the first RF transmission lines including first segments that extend along respective first arcs, where the first arcs are concentrically arranged about a first point;
a plurality of second RF transmission lines, at least some of the second RF transmission lines including second segments that extend along respective second arcs, where the second arcs are concentrically arranged about a second point that is in a different location than the first point;
a plurality of third RF transmission line segments that are constituent parts of a respective plurality of first combiners, wherein a first end of each first RF transmission line is connected to a first end of a respective one of the third RF transmission lines and a first end of each second RF transmission line is connected to a second end of a respective one of the third RF transmission lines,
wherein the printed circuit board comprises a single printed circuit board.
2. The printed circuit board of claim 1 , further comprising a plurality of fourth RF transmission line segments that are constituent parts of a respective plurality of second combiners, wherein a second end of each first RF transmission line is connected to a first end of a respective one of the fourth RF transmission lines and a second end of each second RF transmission line is connected to a second end of a respective one of the fourth RF transmission lines.
3. The printed circuit board of claim 2 , wherein a first rotatable wiper arm is mounted on the printed circuit board above the first RF transmission lines, the first RF transmission lines and the first rotatable wiper arm comprising parts of a first RF band variable phase shifter, and a second rotatable wiper arm is mounted on the printed circuit board above the second RF transmission lines, the second RF transmission lines and the second rotatable wiper arm comprising parts of a second RF band variable phase shifter, and
wherein the first RF band variable phase shifter is configurable independently from the second RF band variable phase shifter.
4. The printed circuit board of claim 3 , wherein the third RF transmission line segments that are constituent parts of the respective first combiners comprise microstrip or stripline transmission line segments, and wherein the fourth RF transmission line segments that are constituent parts of the respective second combiners comprise microstrip or stripline transmission line segments.
5. The printed circuit board of claim 3 , wherein an input of the first RF band variable phase shifter is coupled to a first radio that operates in a first frequency band and an input of the second RF band variable phase shifter is coupled to a second radio that operates in a second frequency band that is different than the first frequency band.
6. The printed circuit board of claim 2 , wherein each first combiner and each second combiner comprises a diplexer filter or a triplexer filter.
7. The printed circuit board of claim 2 , wherein a common port of each combiner is connected to respective sub-arrays of an array of wide band radiating elements.
8. The printed circuit board of claim 7 , wherein at least some of the sub-arrays include only a single radiating element.
9. A printed circuit board for a multi-band antenna system, the printed circuit board comprising:
a first radio frequency (“RF”) band variable phase shifter having a plurality of outputs;
a second RF band variable phase shifter that is configurable independently from the first RF band variable phase shifter;
a plurality of first RF transmission lines, each of the first RF transmission lines coupled to a respective one of the outputs of the first RF band variable phase shifter;
a plurality of second RF transmission lines, each of the second RF transmission lines coupled to a respective one of the outputs of the second RF band variable phase shifter;
a plurality of frequency-selective combiners, each of the frequency-selective combiners having a first port that is coupled to a respective one of the first RF transmission lines, a second port that is coupled to a respective one of the second RF transmission lines and a third port,
wherein a first rotatable wiper arm is mounted on the printed circuit board above the first RF transmission lines, the first RF transmission lines and the first rotatable wiper arm comprising parts of the first RF band variable phase shifter, and a second rotatable wiper arm is mounted on the printed circuit board above the second RF transmission lines, the second RF transmission lines and the second rotatable wiper arm comprising parts of the second RF band variable phase shifter.
10. The printed circuit board of claim 9 , wherein the plurality of frequency-selective combiners comprises a plurality of diplexers.
11. The printed circuit board of claim 9 , wherein each diplexer includes microstrip traces on the printed circuit board.
12. The printed circuit board of claim 9 , wherein each diplexer comprises a microstrip cavity filter that includes a microstrip portion that is implemented in the printed circuit board and a cavity housing.
13. The printed circuit board of claim 9 , wherein each diplexer comprises a microstrip printed circuit board and a cavity housing that together are soldered to the printed circuit board.
14. The printed circuit board of claim 9 , wherein each diplexer comprises first and second series notch filters.
15. The printed circuit board of claim 9 , wherein an input of the first RF band variable phase shifter is coupled to a first radio that operates in a first frequency band and an input of the second RF band variable phase shifter is coupled to a second radio that operates in a second frequency band that is different than the first frequency band.
16. A printed circuit board for a multi-band antenna system, the printed circuit board comprising:
a first radio frequency (“RF”) band variable phase shifter section that has a plurality of outputs;
a second RF band variable phase shifter section that has a plurality of outputs; and
a plurality of frequency-selective combiners, each of the frequency-selective combiners having a first port that is coupled to a respective one of the outputs of the first RF band variable phase shifter section, a second port that is coupled to a respective one of the outputs of the second RF band variable phase shifter section and a third port that is configured for coupling to a respective one of a plurality of sub-arrays of radiating elements,
wherein a first moveable arm is mounted above the first RF band variable phase shifter section to form a first RF band variable phase shifter and a second moveable arm is mounted above the second RF band variable phase shifter section to form a second RF band variable phase shifter, the second RF band variable phase shifter configurable independently from the first RF band variable phase shifter,
wherein the printed circuit board comprises a single printed circuit board that includes the first RF band variable phase shifter section, the second RF band variable phase shifter section and the plurality of frequency-selective combiners, and
wherein the first RF band variable phase shifter is coupled to a first radio that operates in a first frequency band and the second RF band variable phase shifter is coupled to a second radio that operates in a second frequency band that is different than the first frequency band.
17. The printed circuit board for a multi-band antenna system of claim 16 , wherein the frequency-selective combiners include microstrip or stripline transmission line segments.
18. The printed circuit board for a multi-band antenna system of claim 16 , wherein each frequency-selective combiner comprises a diplexer filter or a triplexer filter.
19. The printed circuit board for a multi-band antenna system of claim 16 , wherein at least some of the sub-arrays include only a single radiating element.
20. The printed circuit board for a multi-band antenna system of claim 16 , wherein the first moveable arm comprises a first rotatable wiper arm and the second moveable arm comprises a second rotatable wiper arm.