Adaptive tuning networks with direct mapped multiple channel filter tuning
A flexible multi-path RF adaptive tuning network switch architecture that counteracts impedance mismatch conditions arising from various combinations of coupled RF band filters, particularly in a Carrier Aggregation-based (CA) radio system. In one version, a digitally-controlled tunable matching network is coupled to a multi-path RF switch in order to provide adaptive impedance matching for various combinations of RF band filters. Optionally, some or all RF band filters include an associated digitally-controlled filter pre-match network to further improve impedance matching. In a second version, some or all RF band filters coupled to a multi-path RF switch include a digitally-controlled phase matching network to provide necessary per-band impedance matching. Optionally, a digitally-controlled tunable matching network may be included on the common port of the multi-path RF switch to provide additional impedance matching capability. In a third version, CA direct mapped adaptive tuning networks include filter tuning blocks for selected lower frequency bands.
1. A multi-path radio-frequency (RF) adaptive tuning network switch architecture configurable to operate in a carrier aggregation mode and in a non-carrier aggregation mode, including:
(a) a multi-path tunable switch having (1) a plurality of signal ports each configured to be coupled to a corresponding RF band filter and (2) a common port, the multi-path tunable switch configured to concurrently connect at least two selected signal ports to the common port in at least one mode of operation;
(b) a single digitally-controlled tunable matching network coupled to the common port of the multi-path tunable switch and selectively controlled to counteract impedance mismatch conditions arising from coupling more than one selected RF band filter concurrently to the common port; and
(c) at least one digitally-controlled filter pre-match network configured to have matching elements selectively coupled to or uncoupled from a corresponding signal port of the multi-path tunable switch, wherein the at least one digitally-controlled filter pre-match network is uncoupled from the corresponding signal port when operating in a non-carrier aggregation mode.
2. The multi-path radio-frequency (RF) adaptive tuning network switch architecture of claim 1 , wherein the multi-path tunable switch and the single digitally-controlled tunable matching network are integrated on the same integrated circuit die.
3. The multi-path radio-frequency (RF) adaptive tuning network switch architecture of claim 1 , wherein the multi-path tunable switch and the at least one digitally-controlled filter pre-match network are integrated on the same integrated circuit die.
4. The multi-path radio-frequency (RF) adaptive tuning network switch architecture of claim 1 , wherein the digitally-controlled tunable matching network includes at least one of a digitally tunable capacitor and/or a digitally tunable inductor.
5. The multi-path radio-frequency (RF) adaptive tuning network switch architecture of claim 1 , wherein the digitally-controlled tunable matching network is reconfigurable between at least two types of topologies.
6. The multi-path radio-frequency (RF) adaptive tuning network switch architecture of claim 1 , wherein at least one signal port of the multi-path tunable switch includes a corresponding signal port-side digitally-controlled tunable matching network.
7. The multi-path radio-frequency (RF) adaptive tuning network switch architecture of claim 1 , wherein at least one of the at least one digitally-controlled filter pre-match network includes a signal path between an input port and an output port, a switch coupled to signal path, and at least one impedance tuning element coupled to the switch and configured to be coupled to circuit ground.
8. The multi-path radio-frequency (RF) adaptive tuning network switch architecture of claim 7 , wherein at least one of the at least one impedance tuning element includes a digitally adjustable impedance tuning element.
9. The multi-path radio-frequency (RF) adaptive tuning network switch architecture of claim 1 , further including at least one band filter coupled to one of the at least one digitally-controlled filter pre-match network.