Electrically tunable radio-frequency components and circuits
An electrically controllable RF-circuit element that includes at least one layer of an electrochromic material sandwiched between two corresponding layers of a solid-electrolyte material and placed adjacent and along a length of RF transmission line. In one example embodiment, the electrically controllable RF-circuit element operates as a tunable band-stop (e.g., notch) filter whose stop band can be spectrally moved by changing one or more dc-bias voltages applied across the corresponding layer stack(s). In another example embodiment, the electrically controllable RF-circuit element operates as a tunable phase shifter whose phase-shifting characteristics can be changed by changing one or more dc-bias voltages applied across the corresponding layer stack(s).
1. An apparatus comprising an electrical circuit connected to process an electrical radio-frequency (RF) signal, the electrical circuit including a first length of RF transmission line adjacent and along a first multilayered structure; and
wherein the first multilayered structure comprises a first electrochromic (EC) layer and first and second ion-conductor layers vertically stacked on a substrate, the first EC layer being between the first and second ion-conductor layers and being directly attached to each of the first and second ion-conductor layers.
2. An apparatus comprising an electrical circuit connected to process an electrical radio-frequency (RF) signal, the electrical circuit including a first length of RF transmission line adjacent and along a first multilayered structure; and
wherein the first multilayered structure comprises a first electrochromic (EC) layer and first and second ion-conductor layers vertically stacked on a substrate, the first EC layer being between the first and second ion-conductor layers, each of the first and second ion-conductor layers serving as a respective reservoir of ions for injection into the first EC layer or for ejection from the first EC layer.
3. The apparatus of claim 2 , wherein the first multilayered structure further comprises first and second electrode layers vertically stacked on the substrate such that the first EC layer and the first and second ion-conductor layers are between the first and second electrode layers.
4. The apparatus of claim 2 , wherein the first length of RF transmission line and the first multilayered structure are parts of a circuit element configured to operate on the electrical RF signal as a tunable phase shifter.
5. The apparatus of claim 4 , wherein a phase shift imparted on the electrical RF signal in the circuit element is controllable by a dc-bias voltage applied across the first multilayered structure.
6. The apparatus of claim 5 , wherein the apparatus is configured to change the dc-bias voltage.
7. The apparatus of claim 2 ,
wherein the electrical circuit includes a second length of RF transmission line and a third length of RF transmission line serially connected to one another; and
wherein the first length of RF transmission line is end-connected as a stub between the second and third lengths of RF transmission line.
8. The apparatus of claim 7 ,
wherein the electrical circuit includes a fourth length of RF transmission line and a fifth length of RF transmission line;
wherein the fourth length of RF transmission line is serially connected with the second and third lengths of RF transmission line; and
wherein the fifth length of RF transmission line is end-connected as a stub between the third and fourth lengths of RF transmission line.
9. The apparatus of claim 8 , wherein the fifth length of RF transmission line is adjacent and along a second multilayered structure, the second multilayered structure comprising an EC layer.
10. The apparatus of claim 7 , wherein the first, second, and third lengths of RF transmission line and the first multilayered structure are parts of a circuit element configured to operate on the electrical RF signal as a tunable band-stop filter.
11. The apparatus of claim 10 , wherein spectral position of a stop band of the tunable band-stop filter is controllable by a dc-bias voltage applied across the first multilayered structure.
12. The apparatus of claim 11 , wherein the apparatus is configured to change the dc-bias voltage.
13. The apparatus of claim 7 , wherein the stub comprises a capacitor connected to electrically decouple the second and third lengths of RF transmission line from a dc voltage across the first multilayered structure.
14. The apparatus of claim 2 , wherein the first multilayered structure further comprises a second EC layer and third and fourth ion-conductor layers vertically stacked on the substrate, the second EC layer being between the third and fourth ion-conductor layers and being at a different offset distance from the substrate than the first EC layer.
15. The apparatus of claim 14 , wherein the first multilayered structure further comprises first, second, and third electrode layers vertically stacked on the substrate such that:
the first EC layer and the first and second ion-conductor layers are between the first and second electrode layers; and
the second EC layer and the third and fourth ion-conductor layers are between the second and third electrode layers.
16. The apparatus of claim 15 , wherein the apparatus is configured to individually change a dc-bias voltage between the first and second electrode layers and a dc-bias voltage between the second and third electrode layers.
17. The apparatus of claim 15 ,
wherein each of the first and second EC layers comprises an inorganic oxide;
wherein each of the first, second, third, and fourth ion-conductor layers comprises a solid electrolyte material; and
wherein each of the first, second, and third electrode layers comprises a metal or a metallic alloy.
18. An apparatus comprising an electrical circuit connected to process an electrical radio-frequency (RF) signal, the electrical circuit including a first length of RF transmission line adjacent and along a first multilayered structure, a second length of RF transmission line, and a third length of RF transmission line;
wherein the second and third lengths of RF transmission line are serially connected to one another;
wherein the first length of RF transmission line is end-connected as a stub between the second and third lengths of RF transmission line; and
wherein the first multilayered structure comprises a first electrochromic (EC) layer and a first ion-conductor layer vertically stacked on a substrate.
19. The apparatus of claim 18 , wherein the first, second, and third lengths of RF transmission line and the first multilayered structure are parts of a circuit element configured to operate on the electrical RF signal as a tunable band-stop filter.
20. The apparatus of claim 18 ,
wherein the first multilayered structure further comprises a second ion-conductor layer; and
wherein the first EC layer and the first and second ion-conductor layers are vertically stacked on the substrate such that the first EC layer is between the first and second ion-conductor layers.
21. The apparatus of claim 18 ,
wherein the electrical circuit includes a fourth length of RF transmission line and a fifth length of RF transmission line;
wherein the fourth length of RF transmission line is serially connected with the second and third lengths of RF transmission line; and
wherein the fifth length of RF transmission line is end-connected as a stub between the third and fourth lengths of RF transmission line.
22. The apparatus of claim 21 , wherein the fifth length of RF transmission line is adjacent and along a second multilayered structure, the second multilayered structure comprising a second EC layer.
23. An apparatus comprising an electrical circuit connected to process an electrical radio-frequency (RF) signal, the electrical circuit including a length of RF transmission line adjacent and along a multilayered structure;
wherein the multilayered structure comprises first and second electrochromic (EC) layers and first, second, and third electrode layers vertically stacked on a substrate, the second electrode layer being between the first and third electrode layers, the first EC layer being between the first and second electrode layers, the second EC layer being between the second and third electrode layers; and
wherein the length of RF transmission line comprises the second electrode layer.
24. The apparatus of claim 23 , wherein the multilayered structure further comprises first and second ion-conductor layers vertically stacked on the substrate, the first EC layer being between the first and second ion-conductor layers, the first and second ion-conductor layers being between the first and second electrode layers.
25. The apparatus of claim 23 , wherein the multilayered structure further comprises third and fourth ion-conductor layers vertically stacked on the substrate, the second EC layer being between the third and fourth ion-conductor layers, the third and fourth ion-conductor layers being between the second and third electrode layers.