Abstract: An apparatus and method for controlling an output of a magnetron of a microwave oven is provided. The method includes setting an initial input current to generate an output higher than rated output. Thereafter, the magnetron is driven using initial input current of the setting. The output of the magnetron is varied within a preset time to prevent overheating caused by driving of the magnetron.

Abstract: In a magnetron 41, when a radius of a flat portion 45b of a pole piece 45 is Rp, a radius of the inner circumference of a large-diameter equalizing ring 51 is Rs2, Rp?Rs2, a radius of the outer circumference of a small-diameter equalizing ring is Rs1, a radius of a circle inscribed in a leading edge of an anode vane is Ra, and a minimum length between the pole pieces in the axial direction is Lg, the values of Ra, Rs1, Rs2, and Lg are set such that the following Expressions 1 and 2 are established: 1.85Ra?(Rs1+Rs2)/2?1.96Ra, and[Expression 1] 2.84Ra?Lg?3.0Ra.

Abstract: The object to the present invention is to provide a magnetron which can reduce spurious oscillation such as the ??1 mode which presents a problem particularly in magnetrons and can reduce spurious radiations without placing filters. The magnetron of the present invention includes an anode 1 formed by plural vanes 12 in such a manner that inner ends 12 are radially extended toward the center of the anode shell 11 from the inner wall of a cylindrical anode shell, and a cathode 2 provided at the center of the anode 1. The magnetron of the present invention further includes a pair of pole pieces 4 provided in such a manner that a magnetic field can be applied on the interaction space 2 where the inner ends 12a of the vanes 12 and the cathode 2 face with each other.

Abstract: A magnetron, and a microwave oven and a high frequency heating apparatus each equipped with the same use, a single permanent magnet disposed above or below an anode, a pole piece near the permanent magnet that has a magnetic flux dispersing structure, and another pole piece opposite to the permanent magnet that has a magnetic flux concentrating structure. In accordance with the present invention, even though a single permanent magnet is provided, magnetic flux density is rendered uniform across an activating space, so that the volume and parts of the magnetron are reduced and the curtailment of manufacturing costs is realized.

Abstract: Cost-effective, simple, low-noise, crossed-field devices such as a microwave magnetron, a microwave oven utilizing same, and crossed-field amplifier 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. At least one permanent perturbing magnet having an azimuthally-varying magnetic field impressed thereupon causes the axial magnetic field to vary azimuthally in the magnetron and completely eliminates the microwave noise and unwanted frequencies. Preferably, the number of axial magnetic field perturbations is based on the number of cavities of the magnetron.

Abstract: A high-frequency heating apparatus includes a magnetron (1), a magnetron holding plate (2), a waveguide (3), a heating chamber (4), and screws (5), and the magnetron (1) is attached to the magnetron holding plate (2) with two screws. Hereby, attachment of the magnetron is facilitated, speed-up of the manufacturing process of the high-frequency heating apparatus can be realized, and production efficiency can be improved. Further, in the breakdown repair requiring exchange of the magnetron, working time can be also reduced, so that service to customers can be also improved.

Abstract: A combination hood and microwave oven, in which the construction of a drive circuit relating to an exhaust device is simplified, reducing its manufacturing cost, and in which the number of user's manipulations required to operate the exhaust device is reduced, providing convenience of use to the user. The combination hood and microwave oven includes a variable suction hole whose suction area is variable, a variable suction hole motor allowing a suction area of the variable suction hole to vary, an exhaust motor allowing air sucked through the variable suction hole to be discharged outside the combination hood and microwave oven, an exhaust motor drive unit controlling a rotational speed of the exhaust motor, and a variable suction hole adjusting unit that controls the variable suction hole motor to allow a suction area of the variable suction hole to vary according to the rotational speed of the exhaust motor.

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 magnetron includes a positive polar cylinder, a plurality of vanes, a filament, upper and lower shields, and upper and lower pole pieces. The vanes are disposed in the positive polar cylinder to constitute a positive polar section. The filament is disposed on an axis of the positive polar cylinder to define an activating space. The upper and lower shields cover a top and bottom of the filament, respectively. The upper and lower pole pieces are disposed to induce magnetic flux into the activating space. The upper shield preferably has a diameter ranging from 6.95 mm to 7.10 mm. Additionally, the lower shield preferably has a diameter ranging from 6.95 mm to 7.10 mm.

Abstract: A microwave heating system is provided which uses a heat conductive medium. The heat conductive medium is heated in a heater. The heater includes a shell which forms an enclosure. The enclosure has an upper end and a lower end. A heating coil is located in the enclosure. The heating coil has an upper end and a lower end and has an inverted frusto-conical shape. The upper end of the heating coil is larger than the lower end. Three magnetrons are mounted adjacent the heating coil. One magnetron is located at the upper end of the heating coil and the other two magnetrons are located on opposite sides of the heating coil for directing microwave energy into the heating coil. An electrical distribution system is connected to the magnetron. A return line supplies the heat conductive medium into the heating coil adjacent the lower end of the shell. The heat conductive medium is fed through a feed line to a storage tank and into a two-stage domestic hot water heater.

Abstract: A magnetron that includes a choke coil which is connected at one end to a cathode terminal and at the other end to a capacitor to form an LC circuit. The choke coil is made up of a first core type inductor, a second core type inductor and an air-core inductor, connected to the cathode terminal, all of which are connected in series and where the first and second core type inductors are separated by a 1 mm to 6 mm gap. The first and second core type inductors have a bar like, high-frequency absorbing member located within their respective windings.

Abstract: Distributed high power solid state microwave sources are provided to improve the efficiency of microwave heating applications. A plurality of solid state microwave sources can be distributed throughout and/or adjacent to a microwave environment with the microwave power output of the solid state microwave sources being directed toward the chamber. The distribution of the plurality of solid state microwave devices can be customized to the specific size and shape of the microwave chamber and/or specific regions/compartments of the microwave chambers.

Abstract: A microwave device for de-icing and keeping areas of hollow body structures free from ice keeps atmospherically exposed leading edges and adjacent areas free of ice by means of a coolant circuit. The surface segments between the adjacent areas are kept free from ice as a result of the effects of a microwave device on the wall of the surface segments and the heating that occurs by the exposure to microwave radiation. A series of consecutive microwave-tight chambers is disposed behind the wall of the exposed area. A microwave source supplies microwaves to the chambers with the aid of a decoupling structure disposed therein, resulting in high/multimode excitation. The waste heat of the microwave sources is collected by means of a coolant circuit and transported to the r areas adjacent the leading edge for permanent heating in order to keep the surfaces free from ice. The microwave sources are cyclically operated.

Abstract: A microwave oven having an improved configuration of its mounting bracket to couple a magnetron to a waveguide, to reduce the number of operations to couple the magnetron to a waveguide, and which is stable in a fixed state of the mounting bracket to obtain a more efficient cooling effect for the magnetron. The microwave oven includes an oven body, an inner case disposed in the oven body, which defines a cooking chamber therein and an electric component chamber at its outside, a mounting bracket attached to the electric component chamber, which is provided with one or more pockets and is provided near the pocket with a reinforcing section to prevent bending deformation of the mounting bracket, and a magnetron mounted on the mounting bracket, which has one or more coupling portions to be inserted into the pocket of the mounting bracket.

Abstract: A magnetron for use in, for example, microwave ovens, includes a positive polar cylinder, a plurality of vanes, and large-diameter and small-diameter strip rings. The vanes constitute a positive polar section, along with the positive polar cylinder. The large-diameter and small-diameter strip rings are disposed on an upper portion and a lower portion of the vanes, respectively, to alternatively and electrically connect the vanes to one another. The inside and outside diameters of the large-diameter strip ring are in a range of 17.1 mm to 18.01 mm and 18.6 mm to 19.6 mm, respectively. The inside and outside diameters of the small-diameter strip ring are in a range of 13.4 mm to 14.4 mm and 14.9 mm to 15.9 mm, respectively. The height of the large-diameter and small-diameter strip rings is in a range of 1.50 mm to 1.60 mm. The distance between the large-diameter strip ring and the small-diameter strip ring is maintained in an error range of 2.20 mm.

Abstract: A magnetron, and a microwave oven and a high frequency heating apparatus each equipped with the same use, a single permanent magnet disposed above or below an anode, a pole piece near the permanent magnet that has a magnetic flux dispersing structure, and another pole piece opposite to the permanent magnet that has a magnetic flux concentrating structure. In accordance with the present invention, even though a single permanent magnet is provided, magnetic flux density is rendered uniform across an activating space, so that the volume and parts of the magnetron are reduced and the curtailment of manufacturing costs is realized.

Abstract: The invention relates to a device (1) for producing high frequency microwaves comprising a cathode arrangement with heatable cathodes (15) for emitting electrons, two grid arrangements for controlling and focusing fluxes of electrons and an anode (3) for receiving the electrons flowing through the grid arrangements. The cathode arrangement and the first grid arrangement, in addition to a locking element or a throttle element (16), define an input cavity (12) forming a resonant cavity. The anode (3) and the second grid arrangement define an output cavity also forming a resonant cavity. Said cathode arrangement comprises a mounting for the cathode (15) such that a deformation of the cathode (15) is avoided by reducing the distance between the heatable cathode and the grids (18).

Abstract: A wall-mounted microwave oven includes a body partitioned into a cooking cavity and a machine room, a magnetron detachably installed in the machine room, and a control panel detachably mounted on the body in front of the machine room. The magnetron is mounted on a bottom surface of the machine room so as to allow an operator to repair or replace the magnetron without removing the wall-mounted microwave oven from a wall.

Abstract: A magnetron for use in, for example, microwave ovens, includes a positive polar cylinder, a plurality of vanes, and large-diameter and small-diameter strip rings. The vanes constitute a positive polar section, along with the positive polar cylinder. The large-diameter and small-diameter strip rings are disposed on an upper portion and a lower portion of the vanes, respectively, to alternatively and electrically connect the vanes to one another. The inside and outside diameters of the large-diameter strip ring are in a range of 17.1 mm to 18.01 mm and 18.6 mm to 19.6 mm, respectively. The inside and outside diameters of the small-diameter strip ring are in a range of 13.4 mm to 14.4 mm and 14.9 mm to 15.9 mm, respectively. The height of the large-diameter and small-diameter strip rings is in a range of 1.50 mm to 1.60 mm. The distance between the large-diameter strip ring and the small-diameter strip ring is maintained in an error range of 2.20 mm.

Abstract: In a microwave oven system comprising at least one magnetron of a given operating frequency and a mains unit for the at least one magnetron, the at least one magnetron of a given operating frequency is replaceable by a magnetron of another operating frequency. The magnetrons of the different operating frequencies have at least approximately the same mechanical dimensions so that they can be easily replaced quickly. The mains unit can be used for the different magnetrons in unchanged form or in a form involving minor modifications, without any change in the electrical parameters or with a slight change therein, thereby affording interchangeability of the various magnetrons.

Abstract: A microwave oven having an improved configuration of its mounting bracket to couple a magnetron to a waveguide, to reduce the number of operations to couple the magnetron to a waveguide, and which is stable in a fixed state of the mounting bracket to obtain a more efficient cooling effect for the magnetron. The microwave oven includes an oven body, an inner case disposed in the oven body, which defines a cooking chamber therein and an electric component chamber at its outside, a mounting bracket attached to the electric component chamber, which is provided with one or more pockets and is provided near the pocket with a reinforcing section to prevent bending deformation of the mounting bracket, and a magnetron mounted on the mounting bracket, which has one or more coupling portions to be inserted into the pocket of the mounting bracket.

Abstract: In a millimeter wave de-icing system for the front areas of exposed shell structures, at least one independently operable millimeter wave generator is disposed in each shell structure closely adjacent the surfaces of the shell structure to be de-iced or kept free of ice and uncoupling structures are flanged to the microwave generators and have uncoupling openings disposed along the areas of the shell structure to be heated so as to provide a millimeter wave front directed toward this area. The area subjected to the wavefront includes walls of a dielectric composite material with a metallic skin whereby the millimeter wave front penetrates the wall and at least partially is converted into heat within the wall of composite material thereby providing for rapid and effective heat supply to the wall areas of the shell structure to be kept free of ice.

Abstract: Microwave heating apparatus comprising a dielectric microwave applicator provided with a microwave coupling device adapted to feed microwave energy to the applicator. The applicator is provided with a load chamber 8 extending coaxially with regard to the centre axis of the applicator from an upper end to a predetermined distance from a lower end of the applicator, the load chamber is adapted to receive a load to be heated. The dielectric applicator comprises two sections, an upper section 4 provided with the load chamber and a lower section 6 for impedance matching between the coupling device and upper section. In a preferred embodiment the lower section has an increasing cross-sectional area from the coupling device to the intersection to the upper section.

Abstract: In a microwave de-icing system for the front areas of exposed shell structures, at least one independently operable microwave generator is disposed in each shell structure closely adjacent the surfaces of the shell structure to be de-iced or kept free of ice and uncoupling means are flanged to the microwave generators with uncoupling openings disposed along the area of the shell structure to be heated so as to provide a microwave wave front directed toward this area. The area subjected to the wave-front includes walls of a dielectric composite material with a metallic skin whereby the microwave front penetrates into the wall and is converted at least partially into heat within the wall of composite material thereby providing for rapid and effective heat supply to the wall areas of the shell structure to be kept free of ice.

Abstract: A high-frequency heating apparatus includes a magnetron (1), a magnetron holding plate (2), a waveguide (3), a heating chamber (4), and screws (5), and the magnetron (1) is attached to the magnetron holding plate (2) with two screws. Hereby, attachment of the magnetron is facilitated, speed-up of the manufacturing process of the high-frequency heating apparatus can be realized, and production efficiency can be improved. Further, in the breakdown repair requiring exchange of the magnetron, working time can be also reduced, so that service to customers can be also improved.

Abstract: Timing of zero voltage in zero-voltage detector for detecting zero voltage of a commercial power supply 1 is predicted and input from the zero-voltage detector 6 is received only for a given time before and after the predicted timing, whereby overvoltage and overcurrent caused by a zero point shift can be prevented. Thus, it is provided a magnetron drive power supply which is excellent in stability for change in the power supply environment such as noise or instantaneous power interruption.

Abstract: Microwave unit for drying or similar treatment of objects not enclosed in a microwave oven. An air-cooled magnetron 4 enclosed in a magnetron box is used as microwave generator. The cooling air is governed so as to obtain a forced air stream over the colling surfaces. The unit allows higher power output with respect to high frequency energy without a corresponding increase of input power. Method for ameliorating cooling.

Abstract: A magnetron comprising an anode portion, a cathode portion provided in a center of the anode portion, a cylindrical interaction space formed of the anode portion and the cathode portion, and iron magnetic pole pieces located at both ends of the interaction space in an tube axis direction thereof. A relationship between a thickness Tg (mm) of a tapered portion of the magnetic pole pieces and a magnetic flux Bg (mT, at 25° C.) of a center of the interaction space is set to satisfy 155<Bg/Tg<165. It is possible to obtain a magnetron with substantially constant oscillating efficiencies, and it is accordingly possible to stabilize outputs of the microwave oven and to enable easy control of heating food.

Abstract: A system and method for annealing a film on a substrate in a processing chamber, including a microwave generator disposed to provide microwaves to an area within the interior of the chamber. The microwaves have a frequency such that the film is substantially absorptive at the frequency but the substrate is not substantially absorptive at the frequency. A waveguide distributes the microwaves over the surface of the film to provide a substantially uniform dosage of microwaves over the surface of the film. The method includes depositing a film on a substrate in the processing chamber. During at least a portion of the time of the depositing step, microwaves are generated having a frequency such that the film has an absorption peak at the frequency but the substrate lacks a substantial absorption peak at the frequency. The microwaves are directed towards the film.

Abstract: In an apparatus for the selective heating of foods disposed on a serving tray to serving temperature by means of a microwave oven having a gyrotron as a heat source, individual guide means are provided for guiding the microwave radiation individually to particular dishes on the tray and a control computer controls the radiation of, and the heat generated in, the dishes during passages of the tray with the dishes through the microwave oven.

Abstract: A method for depositing corrosion and wear resistant high alloy overlayers on industrial component substrates. Dilution of alloying components from out of the overlayer into the substrate is minimized by use of electroslag surfacing onto horizontally positioned surfaces of the substrate using oscillating wire.

Abstract: A steel bearing member having an erosion resistant surface and a method of making the same is disclosed. The steel bearing member comprising a bearing substrate, a first overlay of hardbanding material having sintered cemented metal carbide pellets in steel and containing hard submicron sized particles, and a second overlay of steel containing hard particles that migrated from the first overlay of hardbanding material during application of the second overlay over the first overlay. A radial bearing member and a method of making the same is disclosed. A composition applied to the bearing substrate to improve the erosion resistance of this surface comprising a steel carrier and carbide pellets composed of submicron hard particles cemented with a metal binder is disclosed.

Abstract: A device of detecting an abnormal state of a microwave oven having relays, a high voltage transformer, and a magnetron, including a voltage sensing part connected between the high voltage transformer and the magnetron to sense a voltage applied to the magnetron's both terminals; and a control part receiving the voltage between the magnetron's terminals from the voltage sensing part to determine an unloaded state where nothing is in a cooking chamber or an overheated state of the magnetron or the cooking chamber, and when determining that the oven is in the abnormal state, turning off the relays to stop the operation of the magnetron; and a method of detecting an abnormal state of a microwave oven including the steps of driving a magnetron to perform a user-selected cooking operation; detecting a voltage between the magnetron's both terminals; computing an average voltage by averaging the voltage between the magnetron's terminals; detecting an abnormal state by comparing the average voltage to a reference volt

Abstract: A rigid internal gear of a wave gear drive is comprise by a tooth-formed member having inner teeth and a circular gear body member, these two members being integrally connected with each other. The tooth-formed member is made of ferrous or copper material having a high strength and wear resistance, while the gear body member is made of lightweight material such as aluminum alloy and the like. These members are connected integrally with each other in a manner that one of these members is formed with baffle means and the other member is made by enveloped casting, or that the member having baffle means is pressed into the other member. These members are therefore surely connected with each other, so that a high torque can be transferred between these members. Also, the lightweight of the rigid internal gear can be achieved without deteriorating strength, wear resistance or the like thereof.

Abstract: A manufacturing method of a rotary shaft having a body portion and a pair of coaxial journals integral with opposite ends of the body portion, wherein a hollow journal base metal is prepared separately from the body portion of the rotary shaft for providing at least one of the coaxial journals of the rotary shaft, a layer of antiabrasive and anticorrosive alloy is formed on a cylindrical surface of the hollow journal base metal by build up welding or hard facing, and the hollow journal base metal is connected at one end thereof with the corresponding one end of the body portion of the rotary shaft by friction welding.

Abstract: Broadly, the present invention is directed to a method for making a metal tag bearing visible indicia thereon and which can be welded onto a workpiece. Such inventive method commences by providing a metal sheet having a top face, a bottom face, and a pair of ends. The top face bears a painted zone upon which is imprinted with visible indicia. At least one of the ends of the bottom face has exposed bare metal. Such bare metal end is folded so as to reveal the bottom face bare metal adjacent to the imprinted painted zone. The thickness of the folded ends is effective for the metal tag to be welded onto a metal workpiece at such folded tag end. Another aspect of the present invention is a metal tag bearing indicia thereon and which can be welded onto a metal workpiece. The tag includes a metal sheet having a top face, a bottom face, and a pair of ends. The top face bears a painted zone upon that is imprinted with visible indicia.

Abstract: A process is provided for laser welding a nickel or cobalt based superalloy article to minimize cracking by preheating the entire weld area to a ductile temperature, maintaining such temperature during welding and solidification of the weld, with the welding utilizing a powder alloy feed and the speed of the laser controlled to less than 10 inches per minute.

Abstract: An electric arc spray gun wherein the spray tips can be precisely aligned is disclosed. The gun body includes converging wire guides located at an acute angle with respect to the horizontal. The diameter of the central portion of each wire guide is slightly less than the bore in which it is received permitting the wire guide to be deflected by the application of pressure to its outer surface. Such pressure is applied by the advancement or retraction of threaded fasteners received through the gun body. By deflecting the wire guides relative to one another, the spray tips can be precisely aligned. The wires which pass through the wire guides and the spray tips come together within the air cap on the gun resulting in the gun producing a very highly defined metallic spray.

Abstract: A microwave heater (22) which uses electromagnetic radiation for heating liquid flowing from a liquid source to a liquid receiver. The microwave heater (22) includes a microwave generator having an interaction region (28) within which the electromagnetic radiation is generated. At least a portion of a conduit (30) which has an inlet (32) connected to the liquid source and an outlet (34) connected to the liquid receiver is deployed within the interaction region (28). The liquid flows through the conduit (30) acting as a dielectric load of the microwave generator so as to be heated by the electromagnetic radiation.

Abstract: This invention relates to a method of embedding electric components or optical components, such as sensors, in a high-temperature metal and the embedded products produced by the method. In the preferred embodiment the components are embedded on a substrate of the high-temperature metal by being placed on a first insulating layer. A second electrically insulating layer, a low thermal conductivity layer, a high thermal conductivity layer, and a primer layer are then deposited in order. The high thermal conductivity layer is in good thermal contact with the substrate. The high-temperature metal is deposited, preferably as molten drops, on the primer layer and the heat from the drops is conducted by high thermal conductivity layer to the substrate while the components are protected by the low thermal conductivity layer.

Abstract: A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Abstract: A filler material is melted into a metallic substrate having a defect under conditions chosen to preclude cracking. In a preferred embodiment of the invention, a laser beam is operated at a relatively low power density and at a relatively large diameter for an extended length of time to produce a molten pool with a low aspect ratio.

Abstract: A microwave oven includes a microwave generating apparatus having a cathode, a first grid for controlling the flow of electrons from the cathode, the first grid having holes for converting electrons from the cathode to the electron beams, a choke structure, positioned between the cathode and the first grid, for serving as a blocking capacitor, wherein the cathode, the first grid and the choke structure define an input cavity functioning as a resonant circuit, a resistor, one end of which is connected to the first grid and the other end thereof is connected to the cathode, for inducing a bias voltage on the first grid, a second grid provided above the first grid and having holes through which the electron beams passing through holes of the first grid pass, an anode for receiving the electrons passing through the holes of the second grid, wherein the second grid and the anode define an output cavity for generating a microwave, the output cavity being electrically insulated from the input cavity, and a driving v

Abstract: A containerless method of producing a crack free metallic article of near-net shape includes melting a filler material into a metallic substrate or seed under conditions chosen to preclude cracking. In a preferred embodiment of the invention, a laser beam is operated at a relatively low power density and at a relatively large beam diameter at the substrate surface for an extended length of time to produce a molten pool with a low aspect ratio. Near-net shape is achieved by applying the process in a closed-loop, multi-axis material deposition system.

Abstract: By equipping a header wherein hollow pipes are welded to a rectangular plate used to mount the header with spaced apart extensions of the welds joining the pipes to the plate located on opposite sides of the bolt holes formed in the plate to mount it on an engine, wherein all the welds are ground flat so that the flattened surfaces of the extensions and the welded ends of the pipes lie in a common plane, it is thereafter possible to connect (bolt) the header to the engine's cylinder head employing bolts without the necessity of gaskets.

Abstract: An apparatus for generating a microwave frequency energy includes a cathode for emitting electrons, a first grid for controlling and focusing the flow of electrons from the cathode, a choke structure for serving as a capacitor, wherein the cathode, the first grid and the choke structure define an input cavity functioning as a resonant circuit.

Abstract: An apparatus for generating a microwave frequency energy includes a cathode for emitting electrons, a first grid for controlling and focusing the flow of electrons from the cathode, a choke structure for serving as a capacitor, wherein the cathode, the first grid and the choke structure define an input cavity functioning as a resonant circuit.

Abstract: A microwave oven includes a cooking chamber, a waveguide, and an apparatus for generating a microwave frequency energy.

Abstract: A microwave oven includes a microwave generating apparatus having a cathode, a first grid for controlling the flow of electrons from the cathode. The first grid has holes for converting electrons from the cathode to the electron beams and a metal film for reducing emission of secondary electron from the first grid. The cathode, the first grid and the choke structure define an input cavity functioning as a resonant circuit. The microwave generating apparatus further includes a resistor for inducing a bias voltage on the first grid, a second grid having holes through which the electron beams passing through holes of the first grid pass, an anode for receiving the electrons passing through the holes of the second grid, and a driving voltage source for providing a driving voltage to the cathode and the anode. The anode is provided with a plurality of protuberances for reducing emission of secondary electron from the anode. The second grid and the anode define an output cavity for generating a microwave.

Abstract: A microwave oven includes a microwave generating apparatus having a cathode, a first grid for controlling the flow of electrons from the cathode, the first grid having holes for converting electrons from the cathode to the electron beams, a choke structure, positioned between the cathode and the first grid, for serving as a blocking capacitor, wherein the cathode, the first grid and the choke structure define an input cavity functioning as a resonant circuit, an array of resistors, one end of which is connected to the first grid and the other end thereof is connected to the cathode, for inducing a bias voltage on the first grid, a controller for controlling the array of resistors to make a plurality of resistance values, a second grid provided above the first grid and having holes through which the electron beams passing through holes of the first grid pass, an anode for receiving the electrons passing through the holes of the second grid, wherein the second grid and the anode define an output cavity for gene