Abstract: An apparatus that enables a homogenous heating and an efficient measurement of organic as well as a mixture of organic and inorganic materials. The apparatus is characterized in that a load, placed in a cavity with very small dimensions in relation to the wavelength in vacuum at applied frequency, is heated by a generated pulsating near field.

Abstract: A high frequency heating apparatus for heating an object to be heated is provided with an electromagnetic wave emission device for emitting electromagnetic waves, a local heating device capable of heating an optional portion of the object by the electromagnetic waves emitted from the emission device, and a control device for controlling the local heating device. The high frequency heating apparatus is further provided with a stage on which the object is placed, a protecting device for protecting the local heating device, a setting device and a detection device, so that the local heating device, the electromagnetic wave emission device or the stage is controlled in accordance with the setting device or the detection device.

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: The applicator directs microwaves through a guide (5) and housing to focus microwaves generated from a microwave emitter to the surface of a target of contaminated concrete. The housing (4) of the applicator has a elliptical base and a truncated elliptical section with two focal areas (F1) and (F2). A component (11) is arranged at the focal area (F1) in the direction of the waveguide to diffuse incident waves to a wall of the housing where they are reflected to the focusing area (F2).

Abstract: A microwave heating apparatus is used for heating a chromatographic column assembly containing a microwave absorbing material. The microwave heating apparatus includes an antenna transmitting a microwave signal and a resonant cavity containing the chromatographic column assembly and the antenna. The chromatographic column assembly extends relative to predetermined electromagnetic field strength contours within the resonant cavity to provide a predetermined heating profile along the length of the chromatographic column assembly. For example, a single-mode chromatographic column microwave oven can be used to heat a coiled chromatography column to a desired temperature gradient along its length. Oven design embodiments utilizing coaxial transmission line structures, coaxial resonators, and cylindrical resonators are described. To control the electromagnetic field gradient in the axial direction, the oven designs provide for varying some part of the oven geometry in the axial direction.

Abstract: An air circulation structure for a microwave oven is disclosed. The structure includes a fan for sucking air into the interior of a machinery compartment installed below a cooking chamber of the microwave oven, a bottom plate having an air suction port through which an air sucked by the fan and radiating heat generated from the electrical elements of the microwave oven is flown into the interior of the cooking chamber, and a rear surface plate having a first air discharge port through which the air passed through an air suction port formed on the bottom plate and circulated in the interior of the cooking chamber is discharged to the outside of the microwave oven, for thereby effectively radiating heat from electrical elements of a microwave oven having a machinery chamber installed below a cooking chamber and dehumidifying from the interior of the cooking chamber.

Abstract: A microwave device and corresponding method for cutting, and especially drilling into, a solid body of non-conductive material employ a microwave source which provides microwave radiation, typically through a waveguide, to a concentrator. The concentrator is configured to concentrate the microwave radiation onto a small region of solid body, thereby generating sufficient heat in that region to liquefy a volume of the material to form a hole. The device and method may be used to perform various drilling, cutting, nailing, joining and welding operations on a wide range of dielectric materials including ceramics, concrete and stone.

Abstract: A microwave oven includes a magnetron for generating electromagnetic wave energy, a waveguide for guiding and directing the electromagnetic wave energy into a cavity body defining a cooking chamber, and an antenna for radiating the electromagnetic wave energy generated by the magnetron into the waveguide. The waveguide includes a first opening for uniformly dispersing the electromagnetic wave energy into the cooking chamber, a second opening for uniformly dispersing the electromagnetic wave energy into the cooking chamber, and a short circuit for providing a short surface to the antenna. The first opening is formed on a portion of the waveguide which contacts the cavity body and extends along a longitudinal direction. The second opening is spaced away from and having a predetermined angle with respect to the first opening.

Abstract: A novel method and apparatus for sterilizing, disinfecting or otherwise heating materials, objects, liquids and the like under pressure is disclosed. The invention utilizes the generation and transmission of single-mode, non-interfering coaxial microwaves from multiple sources into the material to be treated. As a result, a more efficient transfer of microwave energy into the material to be treated is obtained.

Abstract: A microwave heating apparatus is used for heating a chromatographic column assembly containing a microwave absorbing material. The microwave heating apparatus includes an antenna transmitting a microwave signal and a resonant cavity containing the chromatographic column assembly and the antenna. The chromatographic column assembly extends relative to predetermined electromagnetic field strength contours within the resonant cavity to provide a predetermined heating profile along the length of the chromatographic column assembly. For example, a single-mode chromatographic column microwave oven can be used to heat a coiled chromatography column to a desired temperature gradient along its length. Oven design embodiments utilizing coaxial transmission line structures, coaxial resonators, and cylindrical resonators are described. To control the electromagnetic field gradient in the axial direction, the oven designs provide for varying some part of the oven geometry in the axial direction.

Abstract: A microwave oven adapted to radiate microwaves of mutually reverse phases to minimize impedance variation of a waveguide in response to load change of foodstuff, thereby maintaining an output of the microwave at a constant level regardless of load amount of the foodstuff and maintaining an electric field distribution in a cavity at a constant level as well.

Abstract: A microwave oven excitation system comprising a cylindrical microwave launcher for radiating microwave energy into a heating cavity of a microwave oven which is mounted adjacent to the heating cavity, a quarter-wave matching waveguide secured to the launcher, a rectangular waveguide secured to the quarter-wave matching waveguide, and a source of microwave energy at a predetermined operating frequency secured to the rectangular waveguide remotely from the launcher. In addition, a mode stirrer may be optionally installed within the cylindrical microwave launcher. Also, an iris may be optionally mounted between the cylindrical microwave launcher and the heating cavity.

Abstract: A microwave oven excitation system comprising a cylindrical microwave launcher for radiating microwave energy into a heating cavity of a microwave oven which is mounted adjacent to the heating cavity in either a substantially vertical position or a substantially horizontal position, a first hollow waveguide secured to the launcher, a first source of microwave energy at a predetermined operating frequency secured to the first waveguide, a second hollow waveguide secured to the launcher substantially perpendicular to the first waveguide, and a second source of microwave energy at a predetermined operating frequency secured to the second waveguide. Alternatively, a single waveguide is secured to the cylindrical launcher and has only a single source of microwave energy secured thereto. In either case, a mode stirrer can be installed within the cylindrical microwave launcher.

Abstract: The present invention is directed to a device for facilitating the heating of a food product having an interior and an exterior, the device comprising an antenna for receiving microwave energy generated by a microwave source, such as a microwave oven, and converting the microwave energy into an electric current, and at least two probes in contact with the antenna and the interior of the food product for directing the current into the interior of the food product, whereby the interior of the food product is resistively heated.

Abstract: According to a method for the heating of dielectric materials, the heat generation is done by oscillating electromagnetic radiation of one or more frequencies within the frequency range 300 kHz-299 MHz, preferably within the frequency range 1 MHz-299 MHz and best of all within the frequency range 12 MHz-200 MHz. In an apparatus for the heating of dielectric materials, preferably of organic nature, the heat is generated by oscillating electromagnetic radiation within the frequency range 300 kHz-299 MHz. The apparatus comprises a chamber (10) consisting of an upper wall (12), a bottom wall (11) and side walls (13, 14, 15, 16) made of electric conducting materials, which walls together with at least one generator (19) are connected to a common reference potential at which the generator (19) is arranged to feed at least one with the chamber cooperating antenna (17) in order to get the electromagnetic radiation in this chamber.

Abstract: A microwave oven waveguide structure which allows the use of low frequency microwaves which is sufficient for cooking, includes an indent portion in a waveguide which is mounted on one side of the inner housing and to which a microwave generated from the magnetron is transmitted, in a microwave oven having an inner housing for forming a cavity for accommodating food and a magnetron for generating a microwave.

Abstract: A microwave oven for radiating microwaves generated from a magnetron into a cavity to heat and cook foodstuff disposed therein, the microwave oven comprising an antenna disposed between a magnetron and the cavity for converting the microwaves to circularly polarized waves to radiate same into the cavity, the microwave oven having the advantage in that the foodstuff in the cavity is heated by radiation of the circularly polarized waves, thereby enabling a uniform heating of the foodstuff and improving an absorption efficiency of microwave energy.

Abstract: A waveguide of a microwave oven is provided to keep constant output and electric field distribution at a cavity regardless of food load by minimizing change in impedance of waveguides depending on food load for cooking, the waveguide comprising radiating holes of first and second output waveguides formed at top and bottom parts of a lateral wall of the cavity centering the power supply hole of the input waveguide to spray microwaves having the electric fields of opposite phases, whereby change in impedance of the waveguide depending on the change in food load is minimized to keep the output from the microwave oven and the electric field distribution constant regardless of food load.

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 electromagnetic wave generated from a magnetron of a microwave oven is dispersed into the cooking chamber from an opening through a waveguide. A first plurality of ring-shaped steps are formed radially on a top wall inside the cooking chamber. One ring-shaped step with a larger radius of the first ring-shaped steps is lower in height on the basis of a bottom surface of the cooking chamber than another ring-shaped step with a smaller radius, and a central part with the opening is highest in height. A second plurality of ring-shaped steps are formed radially on a bottom face inside the cooking chamber. The waveguide is provided with a third plurality of ring-shaped steps capable of maintaining a maximum electromagnetic field energy. Thus, the microwave is impartially dispersed while maintaining the maximum electromagnetic field energy in the cooking chamber and in the waveguide, and the cooking efficiency is largely improved.

Abstract: There is provided a new and useful method and apparatus for the controlled non-pyrolytic reduction of organic material comprising subjecting the material to microwave radiation in a reducing atmosphere.

Abstract: An even heating apparatus for converting microwave energy emitted from a magnetron to a plurality of resonant modes in a heating chamber of a microwave oven for thereby evenly heating the food in the heating chamber includes an antenna array plate including a plurality of antennas therein. The apparatus evenly heats food in the heating chamber by fixing the antenna array plate having multiple antennas therein spaced from the ceiling of the heating chamber.

Abstract: Disclosed is a wave guide system of a microwave oven which has a partition wall for separating a cavity in which food to be cooked is placed from a control room in which a magnetron for generating microwaves is provided, the partition wall having a first and second microwave feed openings for feeding the microwaves to the food; and a wave guide provided to the partition wall where the first and second microwave feed openings are formed, the wave guide having a horizontal upper wall, a side wall to which the magnetron is attached, and a lower wall having a first inclined portion connected to the side wall, a second inclined portion connected to the partition wall, and a vertical portion provided between the first and the second inclined portion.

Abstract: Disclosed is a wave guide having an improved structure and being used in a microwave oven, by which the food contained in a heating chamber is effectively heated. The wave guide has a housing attached to a side wall of the heating chamber, and has first, second, and third guide plates which are spaced at a predetermined distance apart from each other. The first guide plate has a first wave diffusing opening, the second guide plate has two second wave diffusing openings, and the third guide plate has four third wave diffusing openings. The second wave diffusing openings are off-set from the first wave diffusing opening. The third wave diffusing openings are off-set from the second wave diffusing openings. By the wave guide, superimposed high-frequency microwaves are radiated into the heating chamber, so the heating efficiency is improved and the cooking time is shortened. The microwave oven having the wave guide can prevent a waste of electrical power.

Abstract: There is provided a microwave waste sterilizer comprising an upper outer shell, a lower outer shell, an upper means for guiding microwave energy, a lower means for guiding microwave energy, an upper means for dispersing microwave energy, and a lower means for dispersing microwave energy. There is also provided a method for sterilizing waste materials with dual sources of microwave energy. Further there is provided a method for dispersing microwave energy into a chamber such that the dispersed microwave energy creates a flux field of substantially uniform flux.

Abstract: An H-field electromagnetic heating system for fusion bonding, particularly useful in the sealing of telecommunications cables and closures, comprises a composite bonding material having a bonding matrix and susceptors, the susceptors being magnetically reactive at a frequency above 50 MHz, and an applicator for applying radiant electromagnetic energy to the composite bonding material, at a frequency above 50 MHz (preferably 75-500 MHz). The applicator may take the form of a quarter-wave resonator having an inner conductor and an outer conductor which at least partially surrounds the inner conductor, the two conductors being shorted at a common end. The material to be heated is placed between the conductors. The inner conductor may include a resonator tube which is capacitively coupled to the power supply by a capacitive probe connected to the center conductor of a coaxial connector.

Abstract: A microwave thawing system for thawing bags of frozen blood products features non-invasively monitoring the internal temperature of the blood product during thawing, and controlling the level of warming energy applied to the blood product based on the monitored temperature. The non-invasive monitoring is performed with one or more antennas which receive electromagnetic energy from the frozen blood product during thawing. Because the applied energy level is controlled based on the temperature of the blood, the blood can be thawed rapidly with little risk of damage from overheating. Pressure is applied to the bag to maintain a uniform distribution of blood within the bag and to separate the thawed blood from the still-frozen blood during thawing; for example, the pressure moves the liquid blood to the periphery of the bag and retains the frozen blood in the center of the bag.

Abstract: A wave guide system of a microwave oven is provided, comprising a cavity containing a food to be cooked and having a pair of microwave feed openings formed in one wall thereof; a magnetron having an antenna and positioned between the microwave feed openings in spaced apart relation to the wall having the feed openings, to generate microwaves having a wavelength of .lambda..sub.g ; and a waveguide provided to cover the feed openings, support thereon the magnetron and guide the microwave through the feed openings into the cavity and having a short circuited surface which is spaced apart from the antenna by a distance of .lambda..sub.g /4 and parallel to the antenna. With this arrangement, the microwave generated in the magnetron produce standing waves in the waveguide, and then are emitted into the cavity through the microwave feed openings of the cavity, thereby uniformly heating a food in the cavity.

Abstract: The output matching networks normally included in a microwave power transistor package as well as the transistor combining network therefor are eliminated for heating applications, e.g. microwave ovens. In a preferred embodiment, the transistor dies of four microwave silicon bipolar power transistors are directly connected to the low impedance points of a common patch type antenna element, also referred to as an applicator, located within the wall of a heating chamber in place of a magnetron. Each pair of power transistors are electrically spaced one half wavelength apart and are located transverse to each other on the antenna. The transistors are operated in pairs with a 180.degree. phase difference so that mutually orthogonal longitudinal modes are excited in the antenna. Moreover, the transistors are frequency modulated over their prescribed frequency band to eliminate standing waves in the load, i.e. the article or substance being heated or cooked.

Abstract: A magnetron assembly that is adapted to be mounted on a wall of a waveguide in a microwave oven includes a yoke enclosure in which is disposed a magnetron tube. The yoke enclosure is generally U-shaped with an open top end and open opposite ends to permit air flow through the yoke enclosure and past circular disc shaped cooling fins that are affixed only to an anode assembly about the magnetron tube. Different configured mounting plates can be detachably disposed in the open top end of the yoke enclosure. A filter box has input power terminals for the magnetron tube extending therefrom and is mounted with respect to a bottom wall of the yoke enclosure such that the yoke enclosure can be rotated to various positions relative to the input terminals extending from the filter box.

Abstract: The invention relates to a plasma excitation device comprising at least one electrically conductive wire applicator fed form an energy source in the microwave range and means for creating a magnetic field and adapted to create at least one surface having a constant magnetic field of a flux density that corresponds to electron cyclotron resonance. According to the invention, the wire applicator includes the means for creating the magnetic field, with the main component thereof being situated in a cross-section of the applicator and extending over at least a fraction of the length of the applicator, said applicator thus constituting an applicator both of a microwave electric field and of a static magnetic field.

Abstract: A reaction vessel used in industrial applications is heated by a multiple mode microwave beam that is directed to an interior wall of the reaction vessel. The beam is in an inclined-angular fashion and the wall is arranged so the beam is absorbed and reflected from it many times to provide a helical-like reflection and absorption pattern within the vessel interior to uniformly heat the vessel wall and the material. A microwave isolator connected between a source of the microwave energy and the reaction vessel includes a quartz plate and a seal for compensating disparities in thermal expansion coefficients between the plate and a housing for the plate.

Abstract: An apparatus for mixing concrete adapted to facilitate removal of hardened concrete therefrom includes a metal container and a microwave energy generation device. The metal container is adapted to contain concrete and to enable concrete placed therein to be mixed or agitated, the container having inner walls to which the concrete may adhere when the concrete hardens. The microwave energy generation device generates microwave radiation energy into the metal container and is capable of liberating water molecules from the concrete placed in the container so as to weaken the chemical structure of the concrete to thereby facilitate breakage of the hardened concrete and removal of the concrete from the container.

Abstract: A process for forming a deposited film on a substrate by microwave plasma CVD comprises holding a substrate in a pressure-reducible reactor vessel, introducing microwave energy into the reactor vessel from at least three microwave-introducing means attached thereto for introducing the microwave energy into the reactor vessel while introducing a raw material gas into the reactor vessel, and forming plasma in the reactor vessel by the microwave energy, thereby forming a deposited film on the surface of the substrate.

Abstract: Microwave energy may be used to dielectrically heat a medium, which can remediate the medium. An apparatus or a system employing this concept is well-suited for various environmental applications, such as in-situ remediation of soil, sludge or spills. The system comprises a microwave energy source having a preselected microwave frequency for emitting microwave energy. The system also comprises a wave-guide section having a cross-section dimensioned in accordance with the wavelength of the microwave frequency for transmitting microwave energy. A broadband mode converter may be disposed in alignment with the wave-guide section. An applicator element is disposed in alignment with the broadband more converter for applying microwave energy directly to the medium without confining the medium, thereby removing contaminants from the medium.

Abstract: A microwave oven includes a cavity in which food is accommodated, a magnetron for generating microwaves, and a waveguide to supply microwaves generated from the magnetron into the cavity. The waveguide has substantially a truncated cone configuration in which the cross sectional area at the cavity side is greater than the cross sectional area at the magnetron side, and an output antenna of the magnetron is disposed to project from the bottom of the waveguide at the magnetron side into the inner space of the waveguide. The microwave oven further includes a flat radiation antenna fixed in the inner space of the waveguide around the output antenna of the magnetron while maintaining distances from the waveguide and the output antenna of the magnetron in which no spark is generated. Therefore, the radiation area for emitting the microwaves is increased significantly to improve heating nonuniformity within the cavity.

Abstract: A gas drying device (30) in which wet gas (31) is introduced into a chamber (36) containing desiccant (38) in which the desiccant (38) adsorbs moisture from the wet gas (31) to dry the wet gas (31) and in which energy is utilized to energize and to remove the moisture from the desiccant (38) to dry and to regenerate the desiccant (38) for reuse to dry wet gas (31) includes a microwave generator (52) and an antenna member (48) in communication with microwaves (50) generated by the microwave generator (52) in which at least a portion of the antenna (48) is disposed within the chamber (46).

Abstract: An apparatus and method for heating water using a microwave powered boiler. The apparatus consists of a three cabinet arrangement which permits the dry incorporation of wave guides and the tunneling of microwave energy completely around and into a seamless water chamber. The apparatus can be adapted to provide a hydronic heating system, a forced hot air heating system, a tankless domestic hot water supply and a hot water heater.

Abstract: In the heat treatment of food particularly pre-packed food it is important to control the temperature and to provide uniform heat distribution within the article, By using a number of microwave emission slots in a waveguide which are brought to resonance in the presence of pre-packed articles carried over the slots by a conveyor the rate of rise of temperature within the article is controlled without unnecessary energy loss between articles carried seriatim on the conveyor The slots may be set obliquely to the direction of passage of the article Alternatively the slots may be formed by a series of smaller slots staggered obliquely across the waveguide so that the presence of the article tunes each of the slots in turn as it passes over the waveguide. The slots may be covered with low-loss dielectric material to prevent extraneous matter falling into the slots and to space the article from the slots so as to control power dissipated.

Abstract: A microwave radiation source is introduced into a fry basket within the fry tank of a deep fat fryer to reduce the cooking time of food products within the fry basket. Microwave energy is generated outside the fry tank and coupled into the fry basket by a microwave tuned transition, waveguide and antenna. Microwave chokes seal the basket top cover and microwave antenna to basket interface to confine the microwave energy to the fry basket. An electrical safety interlock prevents generation of microwave energy unless the fry basket is sealed.

Abstract: A microwave responsive heating device useful in microwave packaging for capturing microwave energy in a microwave oven and transmitting the energy to a surface of a food item in a concentrated form to grill, crisp, or brown the surface thereof. The heating device includes an antenna for collecting the microwave energy and a transmission device for transferring the collected energy from the antenna to a surface of a food item. Preferably, the heating device forms an integral portion of the interior of a food package to allow a food item to be stored and cooked therein. The antenna and the transmission device are made from electrically conductive materials and are shaped to, not only, capture and transmit microwave energy efficiently, but also to enhance the intensity of the microwave energy in a concentrated form.

Abstract: A microwave heating element is described which permits a more uniform microwave cooking of a foodstuff to be achieved. The element comprises a layer of electroconductive material having circular openings formed therethrough and arranged in an array that generates thermal energy when exposed to microwave energy and adjacent a foodstuff. An antenna is provided in at least some of the openings to guide microwave energy to and through the openings. The electroconductive material layer usually is adhered to a paperboard layer with an overlying polymeric film layer.