Abstract: A system includes a radio frequency (RF) signal source configured to supply an RF signal. An electrode is coupled to the RF signal source and a transmission path is between the RF signal source and the electrode. 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 is 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 controller is configured to determine that a load in the cavity is a low-loss load based on a rate of change of the RF power values, and cause the RF signal source to supply the RF signal with the one or more desired signal parameters.

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.

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 output of the RF signal source and the electrode(s). The system also includes measurement circuitry coupled to the transmission path and configured to measure one or more parameters that include voltage, current, forward signal power, reflected signal power, and S11 along the transmission path. A system controller is configured to monitor the measurements, and to modify operation of the system when a rate of change of any of the monitored parameter(s) exceeds a predetermined threshold. The impedance matching network may be a single-ended network or a double-ended network.

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: An embodiment of a system includes an RF signal source, a first electrode, a second electrode, and a cavity configured to receive an electrodeless bulb. The RF signal source is configured to generate an RF signal. The first electrode is configured to receive the RF signal and to convert the RF signal into electromagnetic energy that is radiated by the first electrode. The cavity is defined by first and second boundaries that are separated by a distance that is less than the wavelength of the RF signal so that the cavity is sub-resonant. The first electrode is physically positioned at the first boundary, and the second electrode is physically positioned at the second boundary. The first electrode, the second electrode, and the cavity form a structure that is configured to capacitively couple the electromagnetic energy into the electrodeless bulb when the electrodeless bulb is positioned within the cavity.

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 device includes an output circuit that includes an input port at which a signal is received, an output port at which an impedance-adjusted representation of the signal is provided, and a set of bond wires connecting the input and output ports. The device further includes first and second couplers, each including a respective coupling bond wire along the set of bond wires for inductive coupling with the set of bond wires. The first coupler is oriented relative to the distributed-element output circuit to measure forward power provided by the impedance-adjusted representation of the signal via the output port. The second coupler is oriented relative to the output circuit to measure reflected power received via the output port.

Abstract: A radio frequency (RF) heating and defrosting apparatus may include an electrode which, when supplied with RF signal energy, may responsively radiate electromagnetic energy into a cavity of the RF heating and defrosting apparatus. This radiated electromagnetic energy may cause a thermal increase of a load in the cavity. A capacitor may be formed from a portion of the electrode and a conductive plate disposed adjacent to the electrode. The conductive plate may be coupled to a ground reference structure. Dielectric material(s) having a low dielectric constant may be disposed directly between the electrode and the conductive plate.

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 substance treatment apparatus includes an RF signal source, power detection circuitry, a controller, and a transmission path between the RF signal source and a first electrode that radiates electromagnetic energy into a chamber. The RF signal source includes a solid-state amplifier that generates an RF signal. The power detection circuitry detects reflected signal power along the transmission path. Based on the reflected signal power, the controller modifies values of variable components within an impedance matching network electrically coupled along the transmission path to adjust a magnitude of the reflected signal power. The impedance matching network may have a double-ended input connected to a balun, and a double-ended output connected to the first electrode and to a second electrode. Alternatively, the impedance matching network may have a single-ended input connected to the RF signal source, and a single-ended output connected to the first electrode. The second electrode may be grounded.

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: 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.

Abstract: A purification apparatus includes a radio frequency (RF) signal source that generates an RF signal, first and second electrodes, and a conduit. The first electrode receives the RF signal and converts it into electromagnetic energy that is radiated by the first electrode. The conduit includes input and output ports and a chamber. The input and output ports are in fluid communication with the chamber, and the chamber is configured to receive an electrodeless bulb. The chamber is defined by first and second boundaries that are separated by a distance that is less than the wavelength of the RF signal so that the chamber is sub-resonant. The first electrode is physically positioned at the first boundary, and the second electrode is physically positioned at the second boundary. The first and second electrodes and the chamber form a structure that capacitively couples the electromagnetic energy into an electrodeless bulb within the chamber.

Abstract: An embodiment of a system includes an RF signal source, a first electrode, a second electrode, and a cavity configured to receive an electrodeless bulb. The RF signal source is configured to generate an RF signal. The first electrode is configured to receive the RF signal and to convert the RF signal into electromagnetic energy that is radiated by the first electrode. The cavity is defined by first and second boundaries that are separated by a distance that is less than the wavelength of the RF signal so that the cavity is sub-resonant. The first electrode is physically positioned at the first boundary, and the second electrode is physically positioned at the second boundary. The first electrode, the second electrode, and the cavity form a structure that is configured to capacitively couple the electromagnetic energy into the electrodeless bulb when the electrodeless bulb is positioned within the cavity.

Abstract: A device includes an output circuit that includes an input port at which a signal is received, an output port at which an impedance-adjusted representation of the signal is provided, and a set of bond wires connecting the input and output ports. The device further includes first and second couplers, each including a respective coupling bond wire along the set of bond wires for inductive coupling with the set of bond wires. The first coupler is oriented relative to the distributed-element output circuit to measure forward power provided by the impedance-adjusted representation of the signal via the output port. The second coupler is oriented relative to the output circuit to measure reflected power received via the output port.

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, 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 balun includes a dielectric layer having first and second sides, an electrically conductive plate on the second side of the dielectric layer, a first electrically conductive line on the first side and comprising a first end electrically connected to a first terminal and a second end, a second electrically conductive line on the second side and comprising a third end electrically coupled to a second terminal and a fourth end connected to an unbalanced terminal and a micro strip line comprising a fifth end electrically connected to the third end and a sixth end. The first electrically conductive line overlaps the second electrically conductive line. The second and the sixth ends are electrically coupled to the electrically conductive plate. The electrically conductive plate is hollowed in at least a region corresponding to an overlap area of the first electrically conductive line and second electrically conductive line.

Abstract: A balun includes a dielectric layer having first and second sides, an electrically conductive plate on the second side of the dielectric layer, a first electrically conductive line on the first side and comprising a first end electrically connected to a first terminal and a second end, a second electrically conductive line on the second side and comprising a third end electrically coupled to a second terminal and a fourth end connected to an unbalanced terminal and a micro strip line comprising a fifth end electrically connected to the third end and a sixth end. The first electrically conductive line overlaps the second electrically conductive line. The second and the sixth ends are electrically coupled to the electrically conductive plate. The electrically conductive plate is hollowed in at least a region corresponding to an overlap area of the first electrically conductive line and second electrically conductive line.