Low-temperature radio-frequency tuning circuit

Patent metadata

Field	Value
Publication number	US-12080488-B2
Application number	US-202017597541-A
Country	US
Kind code	B2
Filing date	Jul 10, 2020
Priority date	Jul 11, 2019
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

A low-temperature radio-frequency tuning circuit has a capacitor and an inductor. The capacitor has a capacitance between two electrodes associated with a dielectric medium, and the capacitance is tunable. The medium is a quantum paraelectric material. The capacitance is tunable by application of a voltage to apply an electric field to the medium. The capacitance is tunable at a temperature of less than 4 K by use of the quantum paraelectric material as the dielectric medium.

First claim

The invention claimed is:

1. A low-temperature radio-frequency tuning circuit comprising:
a voltage-tunable capacitor and an inductor,
wherein the capacitor is tunable and comprises:
a dielectric medium; and
two electrodes associated with the medium, wherein the capacitor has a capacitance between the electrodes,
wherein the medium comprises a quantum paraelectric material and the capacitance is tunable by application of a voltage to apply an electric field to the medium, and
wherein the capacitance is tunable at a temperature of less than 4 kelvin.

2. The tuning circuit according to claim 1 wherein the medium comprises at least one of strontium titanate, potassium tantalate, and calcium titanate.

3. The tuning circuit according to claim 1 wherein the capacitance is tunable at a temperature of less than 1 kelvin.

4. The tuning circuit according to claim 1 wherein the capacitance is tunable at a temperature of less than 100 millikelvin.

5. The tuning circuit according to claim 1 wherein the capacitance is tunable at a temperature of less than 10 millikelvin.

6. The tuning circuit according to claim 1 wherein application of a bias voltage between the electrodes tunes the capacitance.

7. The tuning circuit according to claim 1 wherein the electrodes are on a same side or on opposite sides of the dielectric medium.

8. The tuning circuit according to claim 1 including at least two of the tunable capacitors formed on a common substrate that is the medium.

9. The tuning circuit according to claim 1 operable in a magnetic field of at least 1 tesla.

10. The tuning circuit according to claim 1 wherein the capacitance is altered by less than 0.5% per 1 tesla change of an applied magnetic field.

11. A low-temperature radio-frequency parametric amplifier comprising at least one of the tuning circuit according to claim 1 .

12. A method of using the tuning circuit according to claim 1 to provide at least one of frequency tuning and tunable impedance matching at a temperature of less than 4 kelvin.

13. The method according to claim 12 wherein the temperature is less than one of 1 kelvin, 100 millikelvin and 10 millikelvin.

14. The method according to claim 12 including applying a bias voltage to apply an electric field to the medium to tune the capacitance of the capacitor.

15. The method according to claim 12 including operating the tuning circuit in a magnetic field of at least 1 tesla.

Assignees

• Ucl Business Ltd

Inventors

• Buitelaar Mark
• Apostolidis Pavlos
• Villis Byron
• Zubko Pavlo

Classifications

• H03H11/28

  Impedance matching networks · CPC title

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title

• H03F19/00

  Amplifiers using superconductivity effects · CPC title

• H03B2201/0208

  the means being an element with a variable capacitance, e.g. capacitance diode · CPC title

• H03J3/185

  with varactors, i.e. voltage variable reactive diodes · CPC title