Varactor tuning for a narrow band filter
AssigneeConductus, Inc.
InventorsChien-Fu Shih, Yongming Zhang, Brian H. Moeckly
Life of this patent
Estimating the term…
Abstract
A method and apparatus for providing dynamic and remote tuning of a cryo-cooled bandpass filter is disclosed. The device includes resonator element and a voltage sensitive element as part of the capacitance in a narrow band filter circuit. A varactor such as a GaAs varactor may be used. Alternatively, a capacitor having a voltage-sensitive dielectric such as SrTiO3 may be used. A computer may be connected to the varactor to provide for automated tuning. The voltage-sensitive capacitor may be integral with the resonator element. The invention provides for remote and dynamic tuning of a narrow bandpass filter while located within its sealed cryo-cooled environment.
Claims25
A tuning device for a cryo-cooled bandpass filter, comprising
- a. a resonator element physically located in a cryo-cooled chamber;
- b. a voltage-sensitive capacitor operatively connected to the resonator element, wherein when a variable voltage is applied to the voltage-sensitive capacitor, the capacitance of the capacitor is varied, and the resonator frequency changes and shifts the passband characteristics of the filter, the voltage-sensitive capacitor also being physically located in the cryo-cooled chamber, whereby the resonator can be tuned remotely after the cryo-cooled chamber is sealed;
- c. a voltage regulator operatively connected to the voltage-sensitive capacitor, wherein the voltage regulator comprises an inductor and a capacitor;
- and
- d. a computer configured and arranged to automatically monitor the output of the filter and to remotely provide real time tuning of the filter.
A tuning device for a bandpass filter, comprising:
- a. a resonator comprising
- i. a resonator element, and
- ii. first and second capacitors, wherein one of the first and second capacitors has a larger capacitance than the other of the first and second capacitors;
- and
- b. a voltage-sensitive device comprising a third capacitor having a voltage sensitive capacitance, wherein the third capacitor is operatively connected in parallel to the second capacitor,
- whereby when a variable voltage is applied to the third capacitor, the capacitance of the third capacitor is varied, and the resonator frequency changes and shifts the passband characteristics of the filter.
Dependencies are inferred from the claim text.