Advanced antenna architecture with low PIM
Embodiments of an Antenna and Filter Unit (AFU) for an Advanced Antenna System (AAS) are disclosed herein. In one embodiment, an AFU for an AAS comprises a first unit and a second unit. The first unit comprises a 1:N power splitter comprising an input coupled, directly or indirectly, to an antenna port of the AFU and N outputs, where N≥2. The first unit also comprises N first board-to-board type connectors electrically connected to the N outputs of the 1:N power splitter, respectively. The second unit comprises N second board-to-board type connectors configured to be electrically coupled to the N first board-to-board type connectors, respectively, and N antenna elements coupled, directly or indirectly, to the N second board-to-board connectors, respectively. By positioning the 1:N power splitter prior to the N first and N second board-to-board type connectors, input power at each of the board-to-board type connectors is reduced, which thereby reduces Passive Intermodulation.
1 . An Antenna and Filter Unit, AFU, for an Advanced Antenna System, AAS, the AFU comprising:
a first unit comprising:
a 1:N power splitter comprising:
an input coupled, directly or indirectly, to an antenna port of a filter; and
N outputs, where N≥2;
N first board-to-board type connectors electrically connected to the N outputs of the 1:N power splitter, respectively;
a second unit comprising:
N second board-to-board type connectors configured to be electrically coupled to the N first board-to-board type connectors, respectively; and
N antenna elements coupled, directly or indirectly, to the N second board-to-board connectors, respectively;
N removable electrically conducting bullets configured to electrically couple the N first board-to-board type connectors and the N second board-to-board type connectors, respectively.
2 . The AFU of claim 1 wherein:
the first unit is a filter unit comprising:
the filter having an input electrically coupled to an input port of the AFU and the antenna port coupled to the input of the 1:N power splitter; and
a filter printed circuit board, PCB, comprising the 1:N power splitter where an output of the filter is electrically coupled to the input of the 1:N power splitter; and
the second unit is an antenna unit.
3 . The AFU of claim 2 wherein the antenna unit further comprises N signal paths connected between the respective ones of the N second board-to-board connectors and the N antenna elements, each signal path comprising:
a phase shifter circuit having an input electrically coupled to a respective one of the N outputs of the 1:N power splitter and an output electrically coupled to a respective one of the N first board-to-board type connectors.
4 . The AFU of claim 3 wherein the antenna unit further comprises:
a radome;
an antenna PCB comprising the N signal paths;
an antenna backplate; and
an antenna filter support that mechanically connects the antenna unit and the filter unit.
5 . The AFU of claim 1 wherein:
the first unit comprises:
a filter unit comprising a filter having an input electrically coupled to the antenna port of the AFU; and
a printed circuit board, PCB, comprising the 1:N power splitter, wherein the input of the 1:N power splitter is configured to be electrically coupled to an output of the filter; and
the second unit is an antenna unit.
6 . The AFU of claim 5 wherein the PCB further comprises:
a phase shifter circuit comprising:
a first terminal configured to be electrically coupled to an output of the filter; and
a second terminal coupled to the input of the 1:N power splitter.
7 . The AFU of claim 6 wherein the antenna unit further comprises:
a radome;
an antenna backplate; and
an antenna filter support that mechanically connects the antenna unit, the PCB, and the filter unit.
8 . The AFU of claim 1 wherein electrical connections formed by the N removable electrically conducting bullets, the N first board-to-board type connectors, and the N second board-to-board type connectors are a primary source of Passive Intermodulation, PIM, distortion in the AAS.