ELECTRICALLY CONTROLLABLE RADIO-FREQUENCY CIRCUIT ELEMENT HAVING AN ELECTROCHROMIC MATERIAL
We disclose an electrically controllable RF-circuit element that includes an electrochromic material. In an example embodiment, the electrically controllable RF-circuit element is configured to operate as a phase shifter whose phase-shifting characteristics can be changed using a dc-bias voltage applied to a multilayered structure containing a layer of the electrochromic material.
1 . An apparatus comprising an electrical circuit configured to process an electrical radio-frequency (RF) signal,
wherein the electrical circuit comprises a multilayered structure that includes a layer of a first electrochromic material; and
wherein the electrical circuit further comprises a first dielectric layer adjacent to a base layer, wherein:
the multilayered structure is adjacent to the base layer; and
an edge of the first dielectric layer is directly connected to a corresponding edge of the multilayered structure.
2 . The apparatus of claim 1 , wherein the multilayered structure is part of a circuit element configured to operate on the electrical RF signal as a variable electrically controllable phase shifter.
3 . The apparatus of claim 2 , wherein:
the circuit element comprises a microstrip line adjacent to the multilayered structure and located at a first non-zero offset distance from the base layer and at a second non-zero offset distance from the layer of the first electrochromic material, the second non-zero offset distance being smaller than the first non-zero offset distance;
the microstrip line is configured to carry the electrical RF signal; and
a phase shift imparted on the electrical RF signal in the circuit element is controllable by a dc-bias voltage between the base layer and the microstrip line.
4 . The apparatus of claim 3 , wherein the apparatus is configured to change the dc-bias voltage.
5 . The apparatus of claim 3 , wherein:
the phase shifter is configured to be in an OFF state at a first value of the dc-bias voltage;
the phase shifter is configured to be in an ON state at a second value of the dc-bias voltage; and
the first value and the second value differ by no more than about 3 V.
6 . (canceled)
7 . The apparatus of claim 1 , wherein the electrical circuit further comprises a first microstrip line adjacent to the multilayered structure, wherein:
a first portion of the first microstrip line is adjacent to a surface of the first dielectric layer and located at a first non-zero offset distance from the base layer; and
a second portion of the first microstrip line is adjacent to a surface of the multilayered structure and located at the first non-zero offset distance from the base layer.
8 . The apparatus of claim 7 ,
wherein the electrical circuit further comprises a second dielectric layer adjacent to the base layer and laterally separated from the first dielectric layer; and
wherein an edge of the second dielectric layer is directly connected to a corresponding edge of the multilayered structure.
9 . The apparatus of claim 8 , wherein a third portion of the first microstrip line is adjacent to a surface of the second dielectric layer and located at the first non-zero offset distance from the base layer.
10 . The apparatus of claim 8 , wherein the first microstrip line has an end on the surface of the multilayered structure.
11 . The apparatus of claim 7 , wherein the electrical circuit further comprises a second microstrip line adjacent to the multilayered structure, wherein:
a first portion of the second microstrip line is adjacent to the surface of the first dielectric layer and located at the first non-zero offset distance from the base layer; and
a second portion of the second microstrip line is adjacent to the surface of the multilayered structure and located at the first non-zero offset distance from the base layer.
12 . The apparatus of claim 11 , wherein:
the first microstrip line has an end on the surface of the multilayered structure; and
the second microstrip line has an end on the surface of the multilayered structure.
13 . The apparatus of claim 11 , wherein the first microstrip line is electrically insulated from the second microstrip line.
14 . The apparatus of claim 11 , wherein the electrical circuit further comprises a dielectric slab formed on the surface of the first dielectric layer over a portion of the first microstrip line and a portion of the second microstrip line to provide ac coupling between the first and second microstrip lines in the amount of about 3 dB.
15 . The apparatus of claim 14 , wherein an edge of the dielectric slab is aligned with the edge of the first dielectric layer that is directly connected to the corresponding edge of the multilayered structure.
16 . The apparatus of claim 1 , wherein the multilayered structure further comprises a layer of a solid-electrolyte material, wherein the layer of the first electrochromic material is sandwiched between the base layer and the layer of the solid-electrolyte material.
17 . The apparatus of claim 16 , wherein the multilayered structure further comprises an ion-storage layer configured to exchange ions with the layer of the solid-electrolyte material.
18 . The apparatus of claim 17 , wherein the ion-storage layer comprises a second electrochromic material different from the first electrochromic material.
19 . The apparatus of claim 17 ,
wherein the ion-storage layer comprises a polymer; and
wherein the first electrochromic material comprises an inorganic oxide.
20 . The apparatus of claim 1 , wherein the first electrochromic material comprises a polymer.
21 . An apparatus comprising an electrical circuit configured to process an electrical radio-frequency (RF) signal, wherein:
the electrical circuit comprises a multilayered structure that includes a layer of a first electrochromic material;
the multilayered structure comprises a base layer adjacent to the layer of the first electrochromic material; and
the electrical circuit comprises a microstrip line adjacent to the multilayered structure and located at a first non-zero offset distance from the base layer and at a second non-zero offset distance from the layer of the first electrochromic material, the second non-zero offset distance being smaller than the first non-zero offset distance.
22 . The apparatus of claim 21 , wherein:
the microstrip line is configured to carry the electrical RF signal; and
a phase shift imparted on the electrical RF signal in the electrical circuit is controllable by a dc-bias voltage between the base layer and the microstrip line.
23 . The apparatus of claim 22 , wherein the apparatus is configured to change the dc-bias voltage.
24 . The apparatus of claim 22 , wherein:
the multilayered structure is part of a circuit element configured to operate on the electrical RF signal as a variable electrically controllable phase shifter;
the phase shifter is configured to be in an OFF state at a first value of the dc-bias voltage;
the phase shifter is configured to be in an ON state at a second value of the dc-bias voltage; and
the first value and the second value differ by no more than about 3 V.