Defrosting apparatus with defrosting operation monitoring and methods of operation thereof

Patent metadata

Field	Value
Publication number	US-11484048-B2
Application number	US-201816172650-A
Country	US
Kind code	B2
Filing date	Oct 26, 2018
Priority date	Sep 14, 2018
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A system and method for defrosting a load are presented. Radio frequency (RF) signals are supplied to a transmission path that is electrically coupled to one or more electrodes that are positioned proximate to a cavity to cause the one or more electrodes to radiate RF electromagnetic energy. An RF power value of the RF signal along the transmission path is periodically measured resulting in RF power values and a rate of change of the RF power values is determined. A low-loss indicator value is determined using the RF power values, wherein the low-loss indicator value is at least partially determined by a dielectric loss of a load in the cavity. A controller determines, using the rate of change of the RF power values and the low-loss indicator value, that the load is in a defrosted state and stops supplying the RF signals.

First claim

What is claimed is:

1. A system comprising:
a radio frequency (RF) signal source configured to supply an RF signal;
an electrode coupled to the RF signal source;
a transmission path between the RF signal source and the electrode, wherein the transmission path is configured to convey the RF signal from the RF signal source to the electrode to cause the electrode to radiate RF electromagnetic energy into a cavity;
power detection circuitry coupled to the transmission path and configured to repeatedly measure RF power values including at least one of forward RF power values and reflected RF power values along the transmission path;
a variable impedance network coupled between the RF signal source and the electrode, the variable impedance network including at least one variable component having at least one component configuration so that the variable impedance network is configurable into a number of distinct network states; and
a controller configured to:
determine a rate of change of the RF power values,
determine a low-loss indicator value using the RF power values, wherein the low-loss indicator value is at least partially determined by a dielectric loss of a load in the cavity by:
measuring a plurality of RF power values, wherein each RF power value in the plurality of RF power values is associated with a different component configuration of the at least one variable component and a different one of the number of distinct network states; and
determining a first number of RF power values in the plurality of RF power values that are greater than a first power value threshold,

determine, using the rate of change of the RF power values and the low-loss indicator value, that the load is in a defrosted state, and
cause the RF signal source to stop supplying the RF signal.

2. The system of claim 1 , wherein the controller is configured to determine the low-loss indicator value by:
for each RF power value in the plurality of RF power values, determining a point score associated with the RF power value, wherein the point score is at least partially determined by the component configuration associated with the RF power value;
using the point score for each RF power value to determine a total point score; and
determining the low-loss indicator value using the total point score.

3. The system of claim 1 , wherein the controller is configured to determine the low-loss indicator value by:
determining a rate of change of the plurality of RF power values; and
determining the low-loss indicator value using the rate of change of the plurality of RF power values.

4. The system of claim 1 , wherein the controller is configured to cause the RF signal source to modify a frequency of the RF signal while the power detection circuitry repeatedly measures the plurality of RF power values.

5. The system of claim 1 , wherein the load is in the defrosted state when a temperature of the load is greater than −4 degrees Celsius.

6. A thermal increase system, comprising:
a radio frequency (RF) signal source configured to supply an RF signal to an electrode to cause the electrode to radiate RF electromagnetic energy;
power detection circuitry configured to repeatedly measure RF power values of the RF electromagnetic energy to generate a plurality of RF power values;
a variable impedance network coupled to the electrode, the variable impedance network being configurable into a number of different network configurations; and
a controller configured to determine that a load proximate to the electrode is in a defrosted state based on a rate of change of the plurality of RF power values and a low-loss indicator value determined using the RF power values, wherein the low-loss indicator value is at least partially determined by a dielectric loss of the load and a comparison of each RF power value of the plurality of RF power values to predetermined thresholds, wherein each RF power value is measured with the variable impedance network in a different network configuration, and to determine one or more signal parameters of the RF signal in response to determining the load is in the defrosted state.

7. The thermal increase system of claim 6 , wherein the controller is configured to determine the low-loss indicator value by:
measuring the plurality of RF power values, wherein each RF power value in the plurality of RF power values is associated with a different configuration of the variable impedance network; and
determining a first number of RF power values in the plurality of RF power values that are greater than a first power value threshold.

8. The thermal increase system of claim 6 , wherein the controller is configured to determine the low-loss indicator value by:
measuring the plurality of RF power values, wherein each RF power value in the plurality of RF power values is associated with a different configuration of the variable impedance network;
for each RF power value in the plurality of RF power values, determining a point score associated with the RF power value;
using the point score for each RF power value to determine a total point score; and
determining that the total point score is less than a threshold point score.

9. The thermal increase system of claim 6 , wherein the controller is configured to cause the RF signal source to modify a frequency of the RF signal while the power detection circuitry repeatedly measures the plurality of RF power values.

10. The thermal increase system of claim 9 , wherein a first RF power value in the plurality of RF power values is associated with a first frequency of the RF signal and a second RF power value in the plurality of RF power values is associated with a second frequency of the RF signal and the low-loss indicator value is at least partially determined by the first RF power value and the second RF power value.

11. The thermal increase system of claim 6 , wherein the controller is configured to modify a configuration of the variable impedance network while the power detection circuitry repeatedly measures the plurality of RF power values.

12. The thermal increase system of claim 11 , wherein a first RF power value in the plurality of RF power values is associated with a first configuration of the variable impedance network and a second RF power value in the plurality of RF power values is associated with a second configuration of the variable impedance network and the low-loss indicator value is at least partially determined by the first RF power value and the second RF power value.

13. The thermal increase system of claim 6 , wherein the load is in the defrosted state when a temperature of the load is greater than −4 degrees Celsius.

Assignees

• Nxp Usa Inc

Inventors

• Tran Hung Hoa
• Piel Pierre Marie Jean
• Mongin Lionel
• Mccarville Jamison Michael

Classifications

• H05B6/1245

  with special coil arrangements · CPC title

• H05B6/62

  Apparatus for specific applications · CPC title

• H05B6/72

  Radiators or antennas · CPC title

• A23L3/005 Primary

  Human Necessities · mapped topic

• A23B2/05 Primary

  by heating using irradiation or electric treatment (drying or kilning A23B2/90) · CPC title