Example systems have a defrost system that can receive a first RF signal at a first frequency to defrost a load. An air treatment device can receive a second RF signal at a second frequency and perform an air treatment process. An RF signal source has a power output, and a switching arrangement selectively electrically connects the defrost system and the first air treatment device to the power output of the RF signal source. A controller can electrically connect one of the defrost system and the first air treatment device to the power output of the RF signal source. When the defrost system is electrically connected, the RF signal source outputs the first RF signal at the first frequency, and when the first air treatment device is electrically connected, the RF signal source outputs the second RF signal at the second frequency.

Example systems have a defrost system that can receive a first RF signal at a first frequency to defrost a load. An air treatment device can receive a second RF signal at a second frequency and perform an air treatment process. An RF signal source has a power output, and a switching arrangement selectively electrically connects the defrost system and the first air treatment device to the power output of the RF signal source. A controller can electrically connect one of the defrost system and the first air treatment device to the power output of the RF signal source. When the defrost system is electrically connected, the RF signal source outputs the first RF signal at the first frequency, and when the first air treatment device is electrically connected, the RF signal source outputs the second RF signal at the second frequency.

The present disclosure relates to a refrigerator. The refrigerator according to an embodiment of the present disclosure includes: a compressor configured to compress a refrigerant; an evaporator configured to perform heat exchange using the refrigerant compressed by the compressor; an RF output device configured to output an RF signal to the evaporator for removing frost on the evaporator; and a controller configured to control the RF output device, wherein the controller is configured to: based on the RF signal, control the frost to phase change into a liquid by heat radiated from a plurality of metal fins of the evaporator; and after the phase change, control temperature of the phase changed liquid to increase by a water molecule movement based on the RF signal. Accordingly, defrosting may be performed using the RF signal.

A lossy dielectric heat source transducer or other transducer can be formed using a multi-layer substrate, such as can include a power layer (to receive an applied electromagnetic input signal), a polyurethane or other polymeric electromagnetic energy absorption layer, and a coupling layer therebetween. The absorption layer can be doped with carbon or another dopant material to increase electromagnetic energy absorption. The coupling layer can be doped with barium titanate or another dopant material to focus electromagnetic energy passing through the coupling layer toward the absorption layer. Frequency-selective addressing of particular transducers can include using a plurality of planar resonators, which can be configured to resonate at the same or different specified frequencies of the applied electromagnetic input. Such addressing of such frequency-sensitive structures can permit location-specific actuation of one or more transducers.

A lossy dielectric heat source transducer or other transducer can be formed using a multi-layer substrate, such as can include a power layer (to receive an applied electromagnetic input signal), a polyurethane or other polymeric electromagnetic energy absorption layer, and a coupling layer therebetween. The absorption layer can be doped with carbon or another dopant material to increase electromagnetic energy absorption. The coupling layer can be doped with barium titanate or another dopant material to focus electromagnetic energy passing through the coupling layer toward the absorption layer. Frequency-selective addressing of particular transducers can include using a plurality of planar resonators, which can be configured to resonate at the same or different specified frequencies of the applied electromagnetic input. Such addressing of such frequency-sensitive structures can permit location-specific actuation of one or more transducers.

An embodiment of a heating system includes a cavity configured to contain a load, a thermal heating system, and an RF heating system. The RF heating system includes a system controller, an RF signal source, one or more electrodes that receive an RF signal from the RF signal source and radiate resultant electromagnetic energy into the cavity, and a variable impedance matching network coupled between the RF signal source and the one or more electrodes. The system controller may monitor an impedance state of the variable impedance matching network to identify the occurrence of a change point. The system controller may estimate the mass of the load and a time and/or energy requirement for cooking the load based on the change point. The system controller may take action by turning off the RF heating system and/or thermal heating system when the time or energy requirement has been met.

A thermal increase system includes one or more multi-level electrodes configured to radiate electromagnetic energy into a cavity in response to receiving a radio frequency (RF) signal from an RF signal source. Each multi-level electrode is positioned adjacent to a wall of the cavity, and each multi-level electrode includes a base portion coupled to an elevated portion. A radiating surface of the elevated portion is at a height of at least 0.5 centimeters (cm) from a radiating surface of the base portion.

A thermal increase system includes one or more multi-level electrodes configured to radiate electromagnetic energy into a cavity in response to receiving a radio frequency (RF) signal from an RF signal source. Each multi-level electrode is positioned adjacent to a wall of the cavity, and each multi-level electrode includes a base portion coupled to an elevated portion. A radiating surface of the elevated portion is at a height of at least 0.5 centimeters (cm) from a radiating surface of the base portion.

A high-frequency heating apparatus according to an embodiment of the present disclosure includes a heating chamber, an electrode, a high-frequency power supply, at least one matching element, and a controller. The heating chamber accommodates a heating target. The high-frequency power supply applies a high-frequency voltage to the electrode. The impedance matcher includes at least one matching element having a matching constant that is variable. The controller stops the high-frequency power supply to complete heating based on a temporal change of the matching constant of the at least one matching element. In this embodiment, a heating target can be heated efficiently.

A high-frequency heating apparatus according to an embodiment of the present disclosure includes a heating chamber, an electrode, a high-frequency power supply, at least one matching element, and a controller. The heating chamber accommodates a heating target. The high-frequency power supply applies a high-frequency voltage to the electrode. The impedance matcher includes at least one matching element having a matching constant that is variable. The controller stops the high-frequency power supply to complete heating based on a temporal change of the matching constant of the at least one matching element. In this embodiment, a heating target can be heated efficiently.