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 multi-band antenna system, comprising:
an array of wide-band radiating elements;
a multi-band electrical tilt circuit, comprising:
a plurality of combiners, each combiner having a combined port, a first radio frequency (“RF”) band port, and a second RF band port, each combined port being coupled to the array of wide-band radiating elements;
a first RF band variable phase shifter having a first input and a first plurality of outputs that are connected to respective ones of the first RF band ports via respective ones of a first plurality of transmission lines; and
a second RF band variable phase shifter having a second input and a second plurality of outputs that are connected to respective ones of the second RF band ports via respective ones of a second plurality of transmission lines,
wherein a portion of the first RF band variable phase shifter and a portion of the second RF band variable phase shifter are mounted in a common medium,
wherein the first RF band variable phase shifter is independently configurable from the second RF band variable phase shifter, and
wherein the first and second RF band variable phase shifters are positioned adjacent each other with a first subset of the combiners arranged on a first side of the first RF band phase shifter and on a first side of the second RF band variable phase shifter and a second subset of the combiners arranged on a second side of the first RF band phase shifter and on a second side of the second RF band variable phase shifter, the second side of the first RF band phase shifter being opposite the first side of the first RF band phase shifter, and the second side of the second RF band phase shifter being opposite the first side of the second RF band phase shifter.
2. The multi-band antenna system of claim 1 , wherein a first RF band port of each combiner in the first subset is adjacent the first side of the first RF band variable phase shifter and a second RF band port of each combiner in the first subset is adjacent the first side of the second RF band variable phase shifter.
3. The multi-band antenna system of claim 2 , wherein a first RF band port of each combiner in the second subset is adjacent the second side of the first RF band variable phase shifter and a second RF band port of each combiner in the second subset is adjacent the second side of the second RF band variable phase shifter.
4. The multi-band antenna system of claim 1 , wherein each combiner comprises a diplexer filter.
5. The multi-band antenna system of claim 1 , wherein each combiner comprises a notch filter.
6. The multi-band antenna system of claim 1 , wherein each combiner comprises a stop-band filter.
7. The multi-band antenna system of claim 6 , wherein each stop-band filter comprises at least one resonant stub.
8. The multi-band antenna system of claim 1 , wherein the array of wide-band radiating elements comprises dual-polarized wide-band radiating elements, wherein the multi-band electrical tilt circuit comprises a first polarization multi-band electrical tilt circuit that is coupled to first polarization elements of the dual-polarized wide-band radiating elements, and wherein the multi-band antenna system further comprises a second polarization multi-band electrical tilt circuit that is coupled to second polarization elements of the dual-polarized wide-band radiating elements.
9. The multi-band antenna system of claim 1 , wherein each combiner is implemented using stepped impedance microstrip on printed circuit board.
10. A multi-band antenna system, comprising:
an array of wide-band radiating elements;
a multi-band electrical tilt circuit, comprising:
a plurality of microstrip-fed cavity diplexer filters implemented on a common printed circuit board, each microstrip-fed cavity diplexer filter having a combined port, a first radio frequency (“RF”) band port, and a second RF band port, each combined port being coupled to the array of wide-band radiating elements;
a first RF band variable phase shifter having a first input and a first plurality of outputs that are connected to respective ones of the first RF band ports via respective ones of a first plurality of transmission lines; and
a second RF band variable phase shifter having a second input and a second plurality of outputs that are connected to respective ones of the second RF band ports via respective ones of a second plurality of transmission lines,
wherein the first RF band variable phase shifter is independently configurable from the second RF band variable phase shifter.
11. The multi-band antenna system of claim 10 , wherein each microstrip-fed cavity diplexer filter includes a cavity housing.
12. The multi-band antenna system of claim 11 , wherein each microstrip-fed cavity diplexer filter includes at least two series notch filters.
13. The multi-band antenna system of claim 12 , wherein each microstrip-fed cavity diplexer filter further includes tuning plugs.
14. The multi-band antenna system of claim 13 , wherein each microstrip-fed cavity diplexer filter includes at least three notch filters in series between the first RF band port and the combined port.
15. The multi-band antenna system of claim 14 , wherein each microstrip-fed cavity diplexer filter includes at least three notch filters in series between the second RF band port and the combined port.
16. The multi-band antenna system of claim 10 , wherein each microstrip-fed cavity diplexer filter comprises a stop-band filter.
17. The multi-band antenna system of claim 16 , wherein each stop-band filter comprises at least one resonant stub.
18. The multi-band antenna system of claim 10 , wherein the first and second RF band variable phase shifters are positioned adjacent each other with a first subset of the microstrip-fed cavity diplexer filters arranged on a first side of the first RF band phase shifter and on a first side of the second RF band variable phase shifter and a second subset of the microstrip-fed cavity diplexer filters arranged on a second side of the first RF band phase shifter and on a second side of the second RF band variable phase shifter, the second side of the first RF band phase shifter being opposite the first side of the first RF band phase shifter, and the second side of the second RF band phase shifter being opposite the first side of the second RF band phase shifter.
19. The multi-band antenna system of claim 18 , wherein a first RF band port of each microstrip-fed cavity diplexer filter in the first subset is adjacent the first side of the first RF band variable phase shifter and a second RF band port of each microstrip-fed cavity diplexer filter in the first subset is adjacent the first side of the second RF band variable phase shifter.
20. The multi-band antenna system of claim 10 , wherein the array of wide-band radiating elements comprises dual-polarized wide-band radiating elements, wherein the multi-band electrical tilt circuit comprises a first polarization multi-band electrical tilt circuit that is coupled to first polarization elements of the dual-polarized wide-band radiating elements, and wherein the multi-band antenna system further comprises a second polarization multi-band electrical tilt circuit that is coupled to second polarization elements of the dual-polarized wide-band radiating elements.