Antenna switching on MIMO devices
A multiple-input, multiple-output (MIMO) transceiver comprises a plurality of RF chains, a plurality of antennas, a plurality of switching components, and control circuitry operatively coupled to the plurality of switching components. In some examples, a total quantity of RF chains included in the plurality of RF chains is equal to a first value, and a total quantity of antennas included in the plurality of antennas is equal to a second value that is less than the first value.
1. A communications device comprising:
a plurality of antennas comprising:
a set of first-band antennas configured to communicate in a first frequency band;
a set of second-band antennas configured to communicate in a second frequency band; and
a set of dual-band antennas configured to communicate in the first frequency band and the second frequency band;
a plurality of receive chains comprising:
a plurality of first-band receive chains configured to receive signals in the first frequency band; and
a plurality of second-band receive chains configured to receive signals in the second frequency band;
a plurality of transmit chains comprising:
a plurality of first-band transmit chains configured to transmit signals in the first frequency band; and
a plurality of second-band transmit chains configured to transmit signals in the second frequency band; and
a plurality of switches configured to connect respective antennas of the plurality of antennas to respective receive chains of the plurality of receive chains and respective transmit chains of the plurality of transmit chains,
wherein the plurality of switches comprises:
a first switch configured to connect one of the set of first-band antennas and one of the plurality of first-band receive chains;
a second switch configured to connect one of the set of second-band antennas and one of the plurality of second-band receive chains;
a third switch configured to connect one of the set of first-band antennas and one of the plurality of first-band receive chains; and
a fourth switch configured to connect one of the set of second-band antennas and one of the plurality of second-band receive chains.
2. The communications device of claim 1 wherein:
each of the plurality of first-band receive chains is switchably coupled to one of the set of first-band antennas or one of the set of dual-band antennas; and
each of the plurality of second-band receive chains is switchably coupled to one of the set of second-band antennas or one of the set of dual-band antennas.
3. The communications device of claim 1 wherein:
each of the plurality of first-band transmit chains is switchably coupled to one of the set of first-band antennas or a first one of the set of dual-band antennas; and
each of the plurality of second-band transmit chains are switchably coupled to one of the set of second-band antennas or a second one of the set of dual-band antennas.
4. The communications device of claim 1 wherein
the first switch is configured to switchably couple each of a first first-band receive chain of the plurality of first-band receive chains, a first first-band transmit chain of the plurality of first-band transmit chains, and a third first-band receive chain of the plurality of first-band receive chains to either a first first-band antenna of the set of first-band antennas or a first dual-band antenna of the set of dual-band antennas;
the second switch is configured to switchably couple each of a third second-band receive chain of the plurality of second-band receive chains, a first second-band transmit chain of the plurality of second-band transmit chains, and a first second-band receive chain of the plurality of second-band receive chains to either the first dual-band antenna of the set of dual-band antennas or a first second-band antenna of the set of second-band antennas;
each of a second first-band receive chain of the plurality of first-band receive chains, a second first-band transmit chain of the plurality of first-band transmit chains, and a fourth first-band receive chain of the plurality of first-band receive chains is switchably coupled to either a second first-band antenna of the set of first-band antennas or a second dual-band antenna of the set of dual-band antennas through the third switch; and
each of a fourth second-band receive chain of the plurality of second-band receive chains, a second second-band transmit chain of the plurality of second-band transmit chains, and a second second-band receive chain of the plurality of second-band receive chains is switchably coupled to either the second dual-band antenna of the set of dual-band antennas or a second second-band antenna of the set of second-band antennas through the fourth switch.
5. The communications device of claim 4 wherein a first first-band transmit chain of the plurality of first-band transmit chains shares a first pole of a first switch of the plurality of switches with a first first-band receive chain of the plurality of first-band receive chains.
6. The communications device of claim 4 wherein a first second-band transmit chain of the plurality of second-band transmit chains shares a second pole of a second switch of the plurality of switches with a first second-band receive chain of the plurality of second-band receive chains.
7. The communications device of claim 4 wherein the second first-band transmit chain of the plurality of first-band transmit chains shares a second pole of a third switch of the plurality of switches with the second first-band receive chain of the plurality of first-band receive chains.
8. The communications device of claim 4 wherein the second second-band transmit chain shares a third pole of the fourth switch of the plurality of switches with the second second-band receive chain of the plurality of second-band receive chains.
9. The communications device of claim 4 , wherein the second first-band transmit chain shares a third pole of the third switch with the second first-band receive chain.
10. The communications device of claim 4 , wherein the second second-band transmit chain of the plurality of second-band transmit chains shares a second pole of the fourth switch with the second second-band receive chain of the plurality of second-band receive chains.
11. The communications device of claim 4 , wherein the first first-band transmit chain of the plurality of first-band transmit chains shares a second pole of the first switch with the first first-band receive chain of the plurality of first-band receive chains.
12. The communications device of claim 4 , wherein the first second-band transmit chain of the plurality of second-band transmit chains shares a first pole of the second switch with the first second-band receive chain of the plurality of second-band receive chains.
13. The communications device of claim 4 , wherein the second first-band transmit chain of the plurality of first-band transmit chains shares a third pole of the third switch with the second first-band receive chain of the plurality of first-band receive chains.
14. The communications device of claim 1 wherein the communications device further comprises a first diplexer and a second diplexer, wherein:
the first diplexer couples one of set of dual-band antennas to the first switch and the second switch; and
the second diplexer couples another of the set of dual-band antennas to the third switch and the fourth switch.
15. The communications device of claim 1 wherein:
each of the first switch, the second switch, the third switch, and the fourth switch is a triple-pole triple-throw (3P3T) switch.
16. The communications device of claim 1 wherein
the first switch is coupled to the third switch; and
the second switch is coupled to the fourth switch.