Abstract: A defrosting system includes an RF signal source, an electrode proximate to a cavity within which a load to be defrosted is positioned, and a transmission path between the RF signal source and the electrode. The system also includes power detection circuitry coupled to the transmission path and configured repeatedly to take forward and reflected RF power measurements along the transmission path. A system controller repeatedly determines, based on the forward and reflected RF power measurements, a calculated rate of change, and repeatedly compares the calculated rate of change to a threshold rate of change. When the calculated rate of change compares favorably with the threshold rate of change, the RF signal source continues to provide the RF signal to the electrode until a determination is made that the defrosting operation is completed, at which time the RF signal source ceases to provide the RF signal to the electrode.

Abstract: A defrosting system includes an RF signal source, two electrodes proximate to a cavity within which a load to be defrosted is positioned, a transmission path between the RF signal source and the electrodes, and an impedance matching network electrically coupled along the transmission path between the output of the RF signal source and the electrodes. The system also includes power detection circuitry coupled to the transmission path and configured to detect reflected signal power along the transmission path. A system controller is configured to modify, based on the reflected signal power, values of variable capacitors of the impedance matching network to reduce the reflected signal power. The impedance matching network may be a single-ended network or a double-ended network.

Abstract: A defrosting system includes an RF signal source, two electrodes proximate to a cavity within which a load to be defrosted is positioned, a transmission path between the RF signal source and the electrodes, and an impedance matching network electrically coupled along the transmission path between the output of the RF signal source and the electrodes. The system also includes power detection circuitry coupled to the transmission path and configured to detect reflected signal power along the transmission path. A system controller is configured to modify, based on the reflected signal power, a value of a variable passive component of the impedance matching network to reduce the reflected signal power. The impedance matching network may be a single-ended network or a double-ended network.

Abstract: A system is configured to perform an operation that results in increasing a thermal energy of a load. The system includes a radio frequency signal source configured to supply a radio frequency signal, an electrode coupled to the radio frequency signal source, and a variable impedance network that includes at least one variable passive component. The variable impedance network is coupled between the radio frequency signal source and the electrode. The system includes a controller configured to determine an operation duration based upon a configuration of the variable impedance network, and to cause the radio frequency signal source to supply the radio frequency signal for the operation duration.

Abstract: A defrosting system includes an RF signal source, one or more electrodes, a transmission path between the RF signal source and the electrode(s), and an impedance matching network coupled along the transmission path. A system controller may modify the impedance matching network to reduce the reflected signal power. The system controller may determine an initial estimate of the mass of the load. Desired signal parameters for the RF signal may be determined based on the initial estimated mass of the load. The system controller may determine a refined estimate of the load mass based on a rate of change of an S11, VSWR, or reflected power parameter measured at the transmission path, or based on elapsed time between matches. Refined signal parameters for the RF signal may be determined based on the refined estimated mass.

Abstract: A defrosting system includes an RF signal source, an electrode proximate to a cavity within which a load to be defrosted is positioned, a transmission path between the RF signal source and the electrode, and an impedance matching network electrically coupled along the transmission path between the output of the RF signal source and the electrode. The system also includes power detection circuitry coupled to the transmission path and configured to detect reflected signal power along the transmission path. A system controller is configured to modify, based on the reflected signal power, an inductance value of the impedance matching network to reduce a ratio of the reflected signal power to the forward signal power. The impedance matching network includes a plurality of fixed-value, lumped inductors positioned within a fixed inductor area.

Abstract: A defrosting system includes an RF signal source, one or more electrodes proximate to a cavity within which a load to be defrosted is positioned, a transmission path between the RF signal source and the electrode(s), and an impedance matching network electrically coupled along the transmission path between the RF signal source output and the electrode(s). A system controller is configured to modify, based on the reflected signal power, values of variable passive components of the impedance matching network to reduce the reflected signal power. The system controller may be configured to estimate the mass of the load by comparing component value(s) of one or more variable passive components of the impedance matching network with a component value table stored in memory, where stored mass values correspond to the stored component values. Desired signal parameters for the RF signal may be determined based on the estimated mass of the load.

Abstract: A system and method for tuning an impedance network of a device is provided. An RF signal is provided through a transmission path connected to an impedance matching network that includes a first variable component and a second variable component. A phase angle between a forward signal and a reflected signal along the transmission path is determined. Based on the phase angle between the forward signal and the reflected signal, the first variable component is modified to improve an impedance match between the RF signal source and the electrode. After modifying the first variable component, a ratio of a power of the reflected signal to a power of the forward signal is determined, and an inductance of the second variable component is modified to reduce the ratio of a power of the reflected signal to a power of the forward signal.

Abstract: A system and method for defrosting or heating are presented. A radio frequency (RF) signal source provides, through a transmission path, an RF signal to an electrode that is proximate to a cavity of a defrosting system. A rate of change of a ratio of a reflected RF power measurement and a forward RF power measurement along the transmission path is determined to have transitioned from a relatively high value to a relatively low value. At a point in time when the determination is made, the RF signal is provided to the electrode for an additional time duration beyond the point in time, and provision of the RF signal to the electrode is ceased when the additional time duration has expired.

Abstract: A system and method for tuning an impedance network of a device is provided. An RF signal is provided through a transmission path connected to an impedance matching network that includes a first variable component and a second variable component. A phase angle between a forward signal and a reflected signal along the transmission path is determined. Based on the phase angle between the forward signal and the reflected signal, the first variable component is modified to improve an impedance match between the RF signal source and the electrode. After modifying the first variable component, a ratio of a power of the reflected signal to a power of the forward signal is determined, and an inductance of the second variable component is modified to reduce the ratio of a power of the reflected signal to a power of the forward signal.

Abstract: A system and method for tuning an impedance network of a device is provided. An RF signal is provided through a transmission path connected to an impedance matching network that includes a first variable component and a second variable component. A phase angle between a forward signal and a reflected signal along the transmission path is determined. Based on the phase angle between the forward signal and the reflected signal, the first variable component is modified to improve an impedance match between the RF signal source and the electrode. After modifying the first variable component, a ratio of a power of the reflected signal to a power of the forward signal is determined, and an inductance of the second variable component is modified to reduce the ratio of a power of the reflected signal to a power of the forward signal.

Abstract: A defrosting system includes an RF signal source, an electrode proximate to a cavity within which a load to be defrosted is positioned, and a transmission path between the RF signal source and the electrode. The system also includes power detection circuitry coupled to the transmission path and configured repeatedly to take forward and reflected RF power measurements along the transmission path. A system controller repeatedly determines, based on the forward and reflected RF power measurements, a calculated rate of change, and repeatedly compares the calculated rate of change to a threshold rate of change. When the calculated rate of change compares favorably with the threshold rate of change, the RF signal source continues to provide the RF signal to the electrode until a determination is made that the defrosting operation is completed, at which time the RF signal source ceases to provide the RF signal to the electrode.

Abstract: A defrosting system includes an RF signal source, one or more electrodes, a transmission path between the RF signal source and the electrode(s), and an impedance matching network coupled along the transmission path. A system controller may modify the impedance matching network to reduce the reflected signal power. The system controller may determine an initial estimate of the mass of the load. Desired signal parameters for the RF signal may be determined based on the initial estimated mass of the load. The system controller may determine a refined estimate of the load mass based on a rate of change of an S11, VSWR, or reflected power parameter measured at the transmission path, or based on elapsed time between matches. Refined signal parameters for the RF signal may be determined based on the refined estimated mass.

Abstract: A system is configured to perform an operation that results in increasing a thermal energy of a load. The system includes a radio frequency signal source configured to supply a radio frequency signal, an electrode coupled to the radio frequency signal source, and a variable impedance network that includes at least one variable passive component. The variable impedance network is coupled between the radio frequency signal source and the electrode. The system includes a controller configured to determine an operation duration based upon a configuration of the variable impedance network, and to cause the radio frequency signal source to supply the radio frequency signal for the operation duration.

Abstract: A defrosting system includes an RF signal source, an electrode proximate to a cavity within which a load to be defrosted is positioned, and a transmission path between the RF signal source and the electrode. The system also includes power detection circuitry coupled to the transmission path and configured repeatedly to take forward and reflected RF power measurements along the transmission path. A system controller repeatedly determines, based on the forward and reflected RF power measurements, a calculated rate of change, and repeatedly compares the calculated rate of change to a threshold rate of change. When the calculated rate of change compares favorably with the threshold rate of change, the RF signal source continues to provide the RF signal to the electrode until a determination is made that the defrosting operation is completed, at which time the RF signal source ceases to provide the RF signal to the electrode.

Abstract: A defrosting system includes an RF signal source, one or more electrodes proximate to a cavity within which a load to be defrosted is positioned, a transmission path between the RF signal source and the electrode(s), and an impedance matching network electrically coupled along the transmission path between the RF signal source output and the electrode(s). A system controller is configured to modify, based on the reflected signal power, values of variable passive components of the impedance matching network to reduce the reflected signal power. The system controller may be configured to estimate the mass of the load by comparing component value(s) of one or more variable passive components of the impedance matching network with a component value table stored in memory, where stored mass values correspond to the stored component values. Desired signal parameters for the RF signal may be determined based on the estimated mass of the load.

Abstract: A defrosting system includes an RF signal source, two electrodes proximate to a cavity within which a load to be defrosted is positioned, a transmission path between the RF signal source and the electrodes, and an impedance matching network electrically coupled along the transmission path between the output of the RF signal source and the electrodes. The system also includes power detection circuitry coupled to the transmission path and configured to detect reflected signal power along the transmission path. A system controller is configured to modify, based on the reflected signal power, values of variable capacitors of the impedance matching network to reduce the reflected signal power. The impedance matching network may be a single-ended network or a double-ended network.

Abstract: A defrosting system includes an RF signal source, two electrodes proximate to a cavity within which a load to be defrosted is positioned, a transmission path between the RF signal source and the electrodes, and an impedance matching network electrically coupled along the transmission path between the output of the RF signal source and the electrodes. The system also includes power detection circuitry coupled to the transmission path and configured to detect reflected signal power along the transmission path. A system controller is configured to modify, based on the reflected signal power, a value of a variable passive component of the impedance matching network to reduce the reflected signal power. The impedance matching network may be a single-ended network or a double-ended network.

Abstract: A system and method for tuning an impedance network of a device is provided. An RF signal is provided through a transmission path connected to an impedance matching network that includes a first variable component and a second variable component. A phase angle between a forward signal and a reflected signal along the transmission path is determined. Based on the phase angle between the forward signal and the reflected signal, the first variable component is modified to improve an impedance match between the RF signal source and the electrode. After modifying the first variable component, a ratio of a power of the reflected signal to a power of the forward signal is determined, and an inductance of the second variable component is modified to reduce the ratio of a power of the reflected signal to a power of the forward signal.

Abstract: A system and method for defrosting or heating are presented. A radio frequency (RF) signal source provides, through a transmission path, an RF signal to an electrode that is proximate to a cavity of a defrosting system. A rate of change of a ratio of a reflected RF power measurement and a forward RF power measurement along the transmission path is determined to have transitioned from a relatively high value to a relatively low value. At a point in time when the determination is made, the RF signal is provided to the electrode for an additional time duration beyond the point in time, and provision of the RF signal to the electrode is ceased when the additional time duration has expired.