Abstract: The microwave applicator for microwaves outputs from a guide (1) comprises an envelope (3) that forces microwaves to converge towards a focal point (16) by means of a complementary central reflector (4). A fraction of the waves reaches this point after reflection on two facets (11, 13), usually curved and concave, of the reflector (4) and the envelope (3), while the other fraction is reflected three times on three facets (10, 12 and 14), the last two facets of which form part of the envelope and one of which is concave for focussing. These devices can be used for removing a concrete surface, because the microwaves cause vaporisation at the focal point (16).

Abstract: Microwave heating apparatus comprising a dielectric microwave applicator provided with a microwave coupling means adapted to feed microwave energy to the applicator. The applicator is provided with a load chamber 8 extending coaxially with regard to the center axis of the applicator from an upper end to a predetermined distance from a lower end of the applicator, said 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 means and upper section. In a preferred embodiment the lower section has an increasing cross-sectional area from the coupling means to the intersection to the upper section.

Abstract: A method of positioning on a microwave waveguide a sensor (20) including an elongate metallic element (23, 24) comprising: selecting a tubular waveguide (12); determining the general orientation of the magnetic field (3) generated during microwave transmission; and positioning the elongate metallic element (20, 23, 24) substantially parallel to the orientation of the magnetic field (3). Connections (23, 24) of the sensor (20) extend longitudinally of the waveguide (12) and are connected to the outer wall (25) of the waveguide and the central conductor (16) of the coaxial cable (15) that powers the waveguide.

Abstract: The present invention relates to a microwave applicator for heating loads being a waveguide transition between the rectangular TE10 and TE20 modes comprising a TE10 mode section and a TE20 mode section. The location of the load (4) being inside said TE20 mode section and with its major axis perpendicularly to the major propagation direction of the TE20 mode, close to a shorting wall (3) of said TE20 mode section and also close to the centreline of said propagation direction.

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 waveguide system for passing microwave energy while blocking foreign particles from a moving gas passing through the system is provided. The system includes first and second waveguide sections and a low loss microwave window disposed between the waveguide sections to allow microwave energy to pass from the first waveguide section through the window to the second waveguide section. The system also includes a gas bypass filtration system having a first port in communication with the first waveguide section, a filter element in communication with the first port, and a second port in communication with the filter element and with the second waveguide section. The system of the invention having these features blocks, by means of the window, a gas flowing through the first waveguide section and forces that gas to flow through the gas bypass filtration system so that it enters the second waveguide section only after passing through the filter. A system designed to include a pillbox window is also provided.

Abstract: The invention relates to a process for drying wood, characterized in that it comprises a pressurizing step to place a sealed chamber (1) under a predetermined pressure by injecting or generating saturating steam and maintaining this pressure for a predetermined time interval, while ensuring a forced circulation of air and saturating steam within the chamber, a heating step to heat the wood core and central zone of the wood pieces by emitting microwaves at frequencies ranging between 400 and 2450 MHz, an evacuation step to carry away the liquid exudates from the wood which run down to the bottom of the chamber (1) where they are collected.

Abstract: Method and device for moisture profiling of fibrous material web to be dried in machines for manufacturing and/or refining of fibrous material web. Method includes subjecting fibrous material web to electromagnetic waves in the form of high-frequency waves. Device includes a fibrous material web support that supports travel of fibrous material web and a rotating cylinder. Rotating cylinder receives fibrous material web from fibrous material web support, and fibrous material web support is arranged outside fibrous material web in relation to the surface of the rotating cylinder. At least one electromagnetic wave transmitter is also included.

Abstract: A discharge tube for a local etching apparatus has a portion positioned within a waveguide which is for the generation of plasma, the said portion being tapered so as to be divergent toward an orifice side of the discharge tube. Even in the event a maximum field strength position of a standing wave in the waveguide should be deviated due to a change in microwave transmission characteristic of the material of the discharge tube or a change in the position of a plunger under the influence of heat, the maximum field strength position lies somewhere in the vicinity of a wall surface of the tapered portion, so that a supplied gas is converted to plasma stably in a short time. When the discharge tube is to be cooled, the cooling can be done effectively with a cooling gas which is cooled by adiabatic expansion while passing through the tapered portion.

Abstract: The present invention relates to an apparatus for heating a sample, such as chemical reaction mixtures, whose dielectric properties varies during the heating process. In particular, the present invention relates to a microwave heating apparatus comprising a microwave generator, a waveguide for guiding the generated microwaves to an applicator, and a deflector formed by a closed loop defining a plane, said deflector having an inherent resonance frequency and a thickness in a direction normal to said plane, the deflector being rotatable around an axis being at least substantially parallel to said plane, the deflector being positioned in the waveguide so as to form a resonant cavity with the sample and the waveguide applicator. The resonance conditions of the resonant cavity and the coupling factor of radiation from the waveguide to the cavity are easily adjustable by rotation of the deflector.

Abstract: A technique for passive suppression of arcs within a microwave frequency waveguide section. The waveguide is configured to have a bend at a point where the naturally, relatively high location occurs within the run. The bend at the high point causes arcs to be trapped as heat naturally collects within the waveguide at such predictable locations. Vent holes formed in the exterior portion of the waveguide at this point allow trapped hot air gases to escape, and cause the arc to be drawn towards the sidewall of the waveguide at a point where the voltage approaches zero. Presenting this region of zero voltage to the arc causes the arc to extinguish itself.

Abstract: A microwave waveguide or resonator for conducting microwaves of high energy density at high temperature for sintering hard materials has a support of a highly heat-resistant material and a laminated body at least partially mounted on the support and having a surface coating consisting of nitrides, carbides, or carbonitrides of elements of the IVa to VIa groups of the periodic system and having a thickness between 0.10 &mgr;m and 100 &mgr;m.

Abstract: A method and apparatus for the removing solvents from coated materials while capturing evaporated vapors in a confined space and maintaining non-explosive conditions within the space. Microwave energy may be applied to a coated material as the coated material passes through a cavity configured to produce an electromagnetic resonance mode. The application of microwaves to the coated material causes rapid evaporation of the solvents. The cavity is also configured to confine the evaporated vapors in a small volume and control the inflow of air into the volume so as to produce an effluent waste stream which includes a relatively high concentration of solvent molecules while maintaining a non-explosive atmosphere within the cavity. The method and apparatus are particularly suited for treating coated web materials, especially continuous webs.

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: Chemical vapor deposition coating is carried out in a cylindrical cavity. The fibers are heated by a microwave source that is uses a TM0N0 mode, where O is an integer, and produces a field that depends substantially only on radius. The fibers are observed to determine their heating, and their position can be adjusted. Once the fibers are uniformly heated, a CVD reagent is added to process the fibers.

Abstract: A microwave applicator that provides a substantially uniform microwave field distribution over a large area, includes an elongated chamber, preferably operating in the length independent mode. A microwave source generates a microwave field at an output frequency. A waveguide or coaxial cable directs the microwave field from the microwave source into the elongated chamber, either through a side launch, end launch or multi launch. A frequency of the microwave field in the elongated chamber and the output frequency of the microwave source are matched through the use of controlled feedback of critical material and process parameters.

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 applicator including a cylindrical elongated chamber used to process materials therein; a microwave power source capable of producing microwave power having an electric field; a waveguide connected to the chamber couples microwave power into the microwave chamber. The applicator provides microwave energy having a substantially uniform field distribution over a large area for processing materials such as a web or sheet-like product. The uniformity of the applicator is enhanced by the use of matching devices within the applicator to match the regions of the applicator with no load to regions where the load is present in a continuous manner.

Abstract: A microwave processing system comprising a microwave applicator and a microwave source. A microwave source generates a microwave field at an output frequency. A frequency of the microwave field in the elongated chamber and the output frequency of the microwave source are matched through the use of controlled feedback of critical material and process parameters.

Abstract: A microwave applicator includes an elongated chamber, preferably having a cylindrical shape, for processing materials therein. A waveguide, connected to the elongated chamber, couples microwave power into the elongated chamber. The cross-sectional area of the elongated chamber can be mechanically adjusted to control and maintain the microwave field uniformity and resonant mode, preferably the length independent mode TM.sub.010, during the processing of the material. The applicator can thus provide microwave energy having a substantially uniform field distribution over a large area for processing materials, for example, a web or sheet like product, plywood and pre-impregnated cloth, in a continuous manner.

Abstract: A microwave applicator includes an elongated chamber, preferably having a cylindrical shape, for processing materials therein. A waveguide, connected to the elongated chamber, couples microwave power into the elongated chamber. The cross-sectional area of the elongated chamber can be mechanically adjusted to control and maintain the microwave field uniformity and resonant mode, preferably the length independent mode TM.sub.010, during the processing of the material. The applicator can thus provide microwave energy having a substantially uniform field distribution over a large area for processing materials in a non-continuous, semi-continuous or fully continuous manner.

Abstract: A rectangular microwave applicator for processing waste material. The rectangular microwave applicator generally includes an upper cavity and a waste container. The upper cavity defines side walls and a ceiling, the bottom of the upper cavity is open. A screwfeeder tube is positioned on and extends through one of the side walls, and a vent is positioned on and extends through another of the side walls. The waste container is rectangular in configuration and is receivable in the bottom of the upper cavity. The waste container holds waste material which is introduced therein via the screwfeeder tube. A microwave choke is carried across the bottom of the upper cavity and is configured to permit the entrance of the waste container in the bottom of the upper cavity. A microwave energy input is at each corner on top of the ceiling of upper cavity and extends therethrough.

Abstract: A non-toxic extermination device is disclosed herein having an RF radiation generator providing microwave, high frequency waves for penetration through solid obstacles such as walls, floors, partitions or the like. The generated waves are characterized as being effective to cause insect internal molecular friction to generate deadly heat.

Abstract: A method and apparatus for applying microwaves to flowable materials within a centrifuge are disclosed. The simultaneous application of microwaves and centrifugation to flowable materials may be utilized to rapidly separate immiscible components from emulsions and dispersions. Microwaves are guided along a waveguide structure within the centrifuge. A meandering path for the waveguide is chosen through the interior of the centrifuge and through the flowable material being centrifuged. Gradual variation in the radial distance of the waveguide from the axis of the centrifuge produces a gradual filling of the cross-section of the waveguide along its length, forming a gentle microwave beach within the waveguide. Excellent microwave coupling and power deposition into the flowable material results. There is no need to contain the flowable material behind a dielectric barrier, normally placed between the incident microwaves and the flowable material, since confinement is provided by centrifugal forces.

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: A microwave applicator (10) including a tunable cavity (12) having by an elongated casing formed from a transition section (14) axially secured between upstream and downstream end sections (16) and by first and second end assemblies (28) each axially movable in the elongated casing. A tube assembly (72) passes through and is rotatably supported within tubes (36) of the end assemblies (28) and passes through the elongated casing. Material in the tube assembly (72) in the elongated casing and between the end assemblies (28) are subjected to microwave power introduced into the transition section (14) by a waveguide (110) via an opening 20. The axis of the tube assembly (72) is adjustably offset from that of the elongated casing and the transition section (14) is adjustably fixed at various circumferential positions to superimpose the material bed in the tube assembly (72) with the area of highest field strength.

Abstract: The generation of volatiles from liquid or solid materials is enhanced and accelerated by exposure to microwave radiation. Normally the energy transfer is effected preferentially toward the liquid or solid materials over the generated gaseous volatiles. Sufficient energy is provided at a selected rate that enhances the generation of volatiles to effect removal as vapor or to produce a pressurized vapor phase. Flow-through separations from a matrix having a microwave-absorbing liquid component are conducted by exposing to microwave radiation to vaporize this component and processing the vapor either by flowing through a selective permeable membrane, or by enclosing the vapor and matrix in a confined space and flowing matrix through a selected separation medium, and recovering residual matrix. These separations are particularly useful in analysis contexts.

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 apparatus for warming of a liquid such as blood or IV fluids in which the warming occurs in-line by means of a microwave heating cavity having a source of microwave energy coupled thereto. A support element in the form of a bobbin forms an assembly with an IV tube wound about the bobbin. This tubing-bobbin assembly is inserted into the microwave heating cavity. A non-invasive, non-perturbing microwave temperature monitor is provided coupled to the microwave heating cavity for monitoring the temperature of liquid flowing in the IV tube. Controls are provided including a desired operating selector for combining signals representative of, not only cavity temperature, but also inlet and outlet temperatures to control the power level of microwave energy delivered to the heating cavity.

Abstract: A method and apparatus for the microwave removal of contaminated concrete surfaces. The apparatus comprises a housing adapted to pass over a support surface. The housing includes a waveguide for directing microwave energy to the surface at an angle maximizing absorption of microwave energy by the surface. The apparatus is further provided with a source of microwave energy operably associated with the waveguide, wherein the microwave energy has a frequency of between about 10.6 GHz and about 24 GHz and acts to remove the uppermost layer from the surface. The apparatus further includes a debris containment assembly comprising a vacuum assembly operably associated with the housing. The vacuum assembly is adapted to remove debris from the area adjacent the surface.

Abstract: There is provided a method and apparatus for forming meat analog products and for texturizing a doughmass wherein the ingredients are mixed, passed through a conduit having a decreasing cross-sectional area while the doughmass is heated therein, the heating being done such that a greater heat intensity is applied to the center of the doughmass than to the doughmass adjacent the walls of the conduit.

Abstract: A non-contact type of deep-diathermy apparatus comprises a microwave source (1), a microwave radiator (2), a microwave focusing device (3), a temperature-measuring device (4) and a computer based control and display device (5). An output port of the microwave radiator (2) is spaced apart from a surface of a diathermized position of a medium to be diathermized by a predetermined distance. The microwave focusing device (3) is placed in front of the output port of the radiator (2) and attached to the output port of the radiator (2) for focusing the microwave from the radiator (2) on a point within the predetermined distance. This apparatus can be used to kill cancer cells or reduce their vitality in deep parts of the medium and will not cause the surface of the medium to be burnt.

Abstract: Apparatus for heating a fiber using microwave energy. The apparatus has a source of microwave energy feeding and applicator. The applicator is configured to concentrate the microwave energy on a chamber holding a fiber. Fibers made or coated using chemical vapor deposition in the apparatus are also disclosed.

Abstract: An electromagnetic wave heater comprises an electromagnetic wave generator a wave guide being connected to the generator for guiding the generated electromagnetic wave to be propagated in a uniform direction, at least one container being provided in the wave guide for accommodating an object to be heated up by irradiation of the electromagnetic wave, the container having at least one tapered portion, a pointed end of which faces to a direction of the propagation of the electromagnetic wave in the wave guide.

Abstract: A non-toxic extermination device is disclosed herein having an RF radiation generator providing microwave, high frequency waves for penetration through solid obstacles such as walls, floors, partitions or the like. The generated waves are characterized as being effective to cause insect internal molecular friction to generate deadly heat.

Abstract: Apparatus for heating a fiber using microwave energy. The apparatus has a source of microwave energy feeding and applicator. The applicator is configured to concentrate the microwave energy on a chamber holding a fiber. Fibers made or coated using chemical vapor deposition in the apparatus are also disclosed.

Abstract: A gas plasma generating system includes a resonant cavity for connection to a source of very high frequency power. A plasma cavity is defined by a wall of an electrically nonconductive material positioned within the resonant cavity for containing an ionizable gas such that in use a plasma is formed in the plasma cavity, the cavity having an exit opening to enable plasma to exit from the system. The plasma cavity comprises a tubular member extending through opposed walls of the resonant cavity, the tubular member receiving at one end a plasma gas, in use, and plasma exiting from the other end, and a movable tuning member whose position can be adjusted to achieve the desired tuning condition, the tubular member defining the plasma cavity extending through the tuning member.

Abstract: The generation of volatiles from liquid or solid materials is enhanced and accelerated by exposure to microwave radiation. Normally the energy transfer is effected preferentially toward the liquid or solid materials over the generated gaseous volatiles. Sufficient energy is provided at a selected rate that enhances the generation of volatiles to produce headspace samples. Alternatively, the rate can be selected so as to disrupt the equilibrium normally present between the liquid or solid phase and the gaseous phase and produce purge and trap samples; the latter process resulting from the selective energy transfer toward the liquid or solid phase over the gaseous phase. The rate of energy transfer can be chosen so as to bring the medium being subjected to microwave radiation to its supercritical state. The material having reached that state can further be used in numerous applications such as supercritical fluid extraction.

Abstract: Method and apparatus for in vivo or in vitro selective deposition of microwave power patterns in lossy dielectric materials, particularly biological tissue. Configured as a needle-like probe, a miniature coaxial cable (1) having a circumferential gap (12) in the shield (2) is wrapped with an electrically thin dielectric substrate (18). The cable center conductor (6) extends immediately past gap (12) and is shorted to cable shield (2). A thin conductive dipole resonator (21) is positioned on substrate (18) and over gap (12) to achieve inductive coupling between the cable center conductor (6) and the dipole resonator (21) through gap (12). The ends of the dipole resonator (21) are capacitively (22) loaded so as to make the current on resonator (37) more uniform and to greatly reduce and stabilize the resonant frequency to be essentially insensitive to the dielectric properties of the surrounding material.

Abstract: A method and apparatus defreeze, reheat and dry products in a closed chamber by moving a microwave source above a layer of product in a to-and-from motion at a specific, constant height from the product layer.

Abstract: A microwave applicator for processing of radioactive waste slurry uses a waveguide network which splits an input microwave of TE.sub.10 rectangular mode to TE.sub.01 circular mode. A cylindrical body has four openings, each receiving 1/4 of the power input. The waveguide network includes a plurality of splitters to effect the 1/4 divisions of power.

Abstract: A fabric dryer employs microwave energy and an auxiliary air convection heater to heat the moisture in the fabric to be dried and provides for control of the microwave energy so that no arcing of metal or other electrically conductive parts occurs as the fabric becomes dryer. The fabric dryer has a controller that receives input from sensors and uses that input to progressively decrease the energy output from the magnetrons in such a manner to prevent arcing of all metal and other electrically conductive materials associated with the fabric, while also controlling the auxiliary air convection heater and an exhaust air recirculator to compensate for the decreased magnetron energy output.

Abstract: A high frequency heating arrangement includes a power converting unit with one or more semiconductor devices which dissipates a slight heat loss. A magnetron receives an output from the power converting unit and supplies electromagnetic waves to a heating chamber. The magnetron dissipates a heat loss that is relatively larger than that of the power converting unit. A cooling fan has a motor which dissipates a heat loss which is relatively smaller than that of the power converting unit. The cooling fan is for cooling the power converting unit and the magnetron. A case is provided in which at least the power converting unit and the magnetron are housed and which is made of an electricity-conductive material. A cooling air passage, along which the motor and the case are arranged, and through which air flows from said cooling fan is provided. Air sent from the cooling fan first cools the motor, then cools at least a portion of the power converting unit, and finally cools the magnetron.

Abstract: A universal electrode holder having a holder body including a top face, a bottom face, perpendicular sidewalls and end walls, wherein one side wall is stepped to define offset lower and upper surface portions joined by a horizontally disposed connecting surface portion; a reference plate having a reference surface disposed to extend transversely of the lower and connecting surface portions; an indexing plate having an indexing surface and being slidably mounted on the lower and connecting surface portions to selectively vary the distance between the reference and indexing surfaces; a clamp device fixed to the holder body for releasably clamping an electrode of rectangular cross section in a mounted position, wherein its opposite edge surfaces engage with the reference and indexing surfaces, its upper and rear side surfaces engage with the connecting and lower surface portions and its front side surface engages with the clamping device; mounting and aligning means including a plurality of ribs depending from t