Abstract: A semiconductor microwave oven and a microwave feeding structure thereof are provided. The microwave feeding structure of the semiconductor microwave oven includes: a chamber body having a door; a semiconductor power source configured to generate a microwave; and a microwave feeding assembly connected between the semiconductor power source and the chamber body, and configured to feed the microwave generated by the semiconductor power source into the chamber body and to convert a first microwave mode output by the semiconductor power source into a second microwave mode adaptive to microwave heating.

Abstract: A method and system for heating a plurality of articles is provided. The method includes discharging microwave energy into a microwave chamber and passing a plurality of articles through the heating zone. At least a portion of the microwave energy discharged into the heating zone may first be phase shifted using one or more phase shifting devices. One embodiment of a rotatable phase shifting device is also provided and includes an elongated fixed member disposed proximate a rotatable housing. The phase shifting device employed by the microwave heating system is configured such that the ratio of the article residence time in the heating zone to the phase shifting rate is at least about 4:1. Rotatable phase shifting devices, or variable phase short circuits, as described herein can also be used in other applications, such as, for example, as impedance or frequency tuning devices.

Abstract: The microwave heating apparatus of the present invention enables microwaves to be propagated onto an object to be heated through a waveguide such that the microwaves propagate to a microwave space reduced by a wavelength controller which is arranged, as a solid-state object, to occupy a predetermined space in the waveguide. Thus, the microwave heating apparatus of the present invention heats the object to be heated which has been placed in the reduced space. The microwave heating apparatus of the present invention utilizes the effects of lengthening the wavelength of the microwaves propagating to the reduced space so as to be longer than the wavelength before entering the reduced space by a predetermined multiple depending on a near-cutoff condition.

Abstract: A microwave heater and method of heating are provided. The microwave heater includes a non-resonant enclosure and a continuous helical antenna within the non-resonant enclosure. The continuous helical antenna is configured to receive therein a load to be heated by microwaves radiated from the continuous helical antenna.

Abstract: An apparatus for exciting a rotating field pattern in a cavity containing an object, the apparatus comprising a radiating element configured to excite an electromagnetic (EM) field pattern in the cavity, wherein the EM field pattern is excited with EM energy at a frequency in the radio-frequency (RF) range, a field rotating element configured to rotate the EM field pattern, wherein the field rotating element has an anisotropy, the anisotropy selected from magnetic anisotropy, electric anisotropy, and a combination of magnetic and electric anisotropies, and a controller configured to determine the EM field pattern according to value indicative of energy absorbable by the object and to control the anisotropy of the field rotating element in order to rotate the EM field pattern.

Abstract: A microwave heating apparatus includes a phase control unit configured to change a phase of a standing wave of microwave introduced into the process chamber by the microwave introduction unit. The phase control unit includes a recessed portion with respect to an inner surface of the bottom wall. The phase control unit is formed of a bottom portion and a fixing plate installed at a lower surface of the bottom portion from the outer side of the process chamber. The phase of the standing wave in the process chamber is changed by the incidence and reflection of the microwave in the recessed portion of the phase control unit surrounded by metallic wall.

Abstract: A semiconductor microwave oven and a microwave feeding structure thereof are provided. The microwave feeding structure of the semiconductor microwave oven includes: a chamber body having a door; a semiconductor power source configured to generate a microwave; and a microwave feeding assembly connected between the semiconductor power source and the chamber body, and configured to feed the microwave generated by the semiconductor power source into the chamber body and to convert a first microwave mode output by the semiconductor power source into a second microwave mode adaptive to microwave heating.

Abstract: A processing system is disclosed, having a process chamber that houses a substrate for exposure of a surface of the substrate to a travelling electromagnetic (EM) wave. The processing system also includes an EM wave transmission antenna configured to launch the travelling EM wave into the process chamber for the travelling EM wave to propagate in a direction substantially parallel to the surface of the substrate. The processing system also includes a power coupling system configured to supply EM energy into the EM wave transmission antenna to generate the travelling EM wave at a prescribed output power and in a prescribed EM wave mode during treatment of the substrate. The processing system also includes an EM wave receiving antenna configured to absorb the travelling EM wave after propagation through the process chamber.

Abstract: A radio frequency heater is disclosed including a vessel for containing material to be heated and a radio frequency radiating surface. The vessel has a wall defining a reservoir. The radio frequency radiating surface at least partially surrounds the reservoir. The radiating surface includes two or more circumferentially spaced petals that are electrically isolated from other petals. The petals are positioned to irradiate at least a portion of the reservoir, and are adapted for connection to a source of radio frequency alternating current. A generally conical tank or tank segment having a conically wound radio frequency applicator is also contemplated. Also, a method of heating an oil-water process stream is disclosed. In this method a radio frequency heater and an oil-water process stream are provided. The process stream is irradiated with the heater, thus heating the water phase of the process stream.

Abstract: An apparatus and a method for heating a load using microwaves is disclosed. The apparatus includes a transmission line, configured to transmit microwaves from a microwave generator to a cavity. A sensing device configured to measure electromagnetic field strengths for providing information about the phase and the amplitude of a reflection coefficient that represents a ratio between the amount of microwaves reflected back towards the microwave generator and the amount of microwaves transmitted in the transmission line from the microwave generator. A control unit configured to detect whether the measured electromagnetic field strengths correspond to a reflection coefficient having a phase within a certain interval of phases and an amplitude within a certain interval of amplitudes. Additionally, certain intervals of phases and amplitudes correspond to an operating region of the microwave generator. The control unit controls feeding of microwaves to the cavity based on this detection.

Abstract: The present invention relates to a cooking appliance employing microwaves. According to the present invention, a cooking appliance employing microwaves comprises: a microwave generator for generating and outputting microwaves, provided with an amplifier for performing frequency oscillation and amplification; and a feeder for outputting the outputted microwaves into a cavity. Accordingly, high power microwaves can be easily generated without a separate frequency oscillator.

Abstract: A radio frequency heater is disclosed including a vessel for containing material to be heated and a radio frequency radiating surface. The vessel has a wall defining a reservoir. The radio frequency radiating surface at least partially surrounds the reservoir. The radiating surface includes two or more circumferentially spaced petals that are electrically isolated from other petals. The petals are positioned to irradiate at least a portion of the reservoir, and are adapted for connection to a source of radio frequency alternating current. A generally conical tank or tank segment having a conically wound radio frequency applicator is also contemplated. Also, a method of heating an oil-water process stream is disclosed. In this method a radio frequency heater and an oil-water process stream are provided. The process stream is irradiated with the heater, thus heating the water phase of the process stream.

Abstract: A method and apparatus for creating uniform heating of an microwave absorptive target. A circularly polarized waveguide mode is created that promotes uniform heating of the microwave absorptive target by rotating a propagated non-uniform field pattern around a central axis of a cylindrical cavity or waveguide. In the process of rotating the field pattern, hot and cold spots in the field pattern are averaged out over time.

Abstract: Low-noise, crossed-field devices such as a microwave magnetron, a microwave oven utilizing same, crossed-field amplifier and a method of converting a noisy magnetron to a low-noise magnetron utilize an azimuthally varying, axial magnetic field. The magnetic configuration reduces and eliminates microwave and radio frequency noise. This microwave noise is present near the carrier frequency and as sidebands, far separated from the carrier. The device utilizes azimuthally varying, axial, magnetic field perturbations. In one embodiment, at least one permanent magnet is placed against the azimuthally-symmetric, axial magnetic field magnetron magnets (four magnets work especially well). This additional permanent magnet(s) causes the axial magnetic field to vary azimuthally in the magnetron and completely eliminates the microwave noise and unwanted frequencies.

Abstract: A microwave delivery system for a cooking appliance includes an electronic control unit and a plurality of magnetrons arranged in a spaced relationship for the introduction of various energy fields into an oven cavity. The electronic control unit creates a phase angle shift between each of the microwave energy fields such that a constructive standing wave propagates about the oven cavity. In this manner, localized hot and cold spots, which can detrimentally affect cooking efficiency, are eliminated without the need for mode stirring or turntables. With this system, the total energy delivered to the oven cavity is the combined energy level of the various microwave energy fields.

Abstract: To uniformly generate plasma using microwaves in a processing vessel. To first to fourth feeding sections 141a to 141d which are evenly placed on the same plane perpendicular to an axial direction of a main coaxial line 123, four microwaves shifted in phase by 0°, 90°, 180°, and 270° are fed from first to fourth microwave supply sections 142a to 142d.

Abstract: Microwave heating apparatus comprising an elongated dielectric microwave applicator with an axial TM type mode, said dielectric applicator is provided with a load chamber for a load to be heated, said load chamber is located in a centered axial position inside the applicator. Two microwave feeding points are arranged at a lower end of the applicator for feeding microwave energy in the axial direction of the applicator so that significant cross-talk between the applied microwaves is avoided.

Abstract: A compact and highly controllable impedance-varying-unit, a microwave device using the same unit, and a high-frequency-heating appliance using the same unit are provided. The impedance varying unit includes a rectangular waveguide-section as a main body made of metallic material, an open end of waveguide-section working on microwave in a microwave cavity, a terminal end of waveguide-section closed by metallic material, a rotary movable body made of non-metallic material, and a driver for the movable body. A rotating angle or a position of the movable body is controlled, so that an impedance at the open end is varied and transmission status of microwave is changed, thereby variably controlling a standing wave distribution. Controlling the standing wave distribution allows an object in the cavity to be selectively heated or uniformly heated. Further, the standing wave produced in the microwave cavity is sequentially varied, so that the object can be selectively heated or uniformly heated.

Abstract: A feed that provides circularly polarized microwave energy such as for energizing a cavity in a microwave oven. The feed includes a transformer to match a linearly polarized rectangular waveguide to an exit waveguide which may be circular or square in cross section. The exit waveguide contains an asymmetrical element that provides symmetry about a plane only. The asymmetrical element therefore introduces a difference in microwave electrical phase of 90 degrees for polarizations which are respectively parallel to and perpendicular to the symmetry plane. The two components add to provide circularly polarized energy at constant magnitude but continually rotating phase. An extension may be used to modify the spread and matching of the energy from the exit waveguide into the enclosure.

Abstract: A microwave oven is disclosed in which the structure of the wave guiding tube is improved such that the variation of the impedance is minimized in spite of the variation of the load of the food, thereby making it possible to maintain the output of the microwave oven at a constant level regardless of the load of the food. The microwaves are divided into a plurality of wave streams, and the wave streams are made to have different phases. The microwave oven includes an input wave guiding tube coupled with a magnetron, for receiving microwaves from the magnetron. A first output wave guiding tube communicates to the input wave guiding tube, for receiving the microwaves from the input wave guiding tube to diffusely irradiate the microwaves into a cavity. A second wave guiding tube communicates to the input wave guiding tube, for converting the microwaves to a phase different from that of the first wave guiding tube to irradiate them into the cavity.

Abstract: An apparatus uses microwave radiation to sterilize metal equipment including sharp edged metal equipment having small quantities of water or water containing organisms on the surface of the equipment. No source of bulk water is required to be heated during the sterilization process and no humid environment is required. The microwave radiation is emitted from locations at opposing ends of a wave guide so that the equipment is present at a nodal point of the near electric field component of the microwave radiation. This configuration reduces the electromagnetic field components that induce sparking and avoids the formation of large potential differences induced by the microwave field between the equipment and the microwave cavity walls. In addition the apparatus employs the electron cloud located in the near field of the magnetron to bombard the surface of the equipment.