US3495062A - Transverse radiator device for heating non-metallic materials in an electromagnetic radiation field - Google Patents

Transverse radiator device for heating non-metallic materials in an electromagnetic radiation field Download PDF

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Publication number
US3495062A
US3495062A US556735A US3495062DA US3495062A US 3495062 A US3495062 A US 3495062A US 556735 A US556735 A US 556735A US 3495062D A US3495062D A US 3495062DA US 3495062 A US3495062 A US 3495062A
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Prior art keywords
coupling
radiator
transverse
metallic materials
radiation field
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Expired - Lifetime
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US556735A
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English (en)
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Herbert August Puschner
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/72—Radiators or antennas
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
    • H01Q13/02—Waveguide horns
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
    • H01Q21/08—Arrays of individually energised antenna units similarly polarised and spaced apart the units being spaced along or adjacent to a rectilinear path
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/78—Arrangements for continuous movement of material

Definitions

  • the invention relates to a transverse radiator device for heating non-metallic materials in an electromagnetic radiation field, more particularly for microwave continuous throughput installations.
  • a segment antenna has been proposed, having a rectilinear excitation element and two secondary radiators arranged symmetrically to the axis of the antenna.
  • the amplitude distribution at the aperture along the broad side of the antenna fluctuates very considerably and as a result of this the antenna is unsuitable for use in uniform heating of material by the radiation.
  • the large structural height of the antenna is disadvantageous.
  • a parabolic horn has been proposed, the amplitude variation of the radiation of which extends approximately sinusoidally over the aperture. As a result of this, it is unsuitable for use as a radiator for installations having a large throughput width.
  • Both radiators have considerable disadvantages with regard to requirements of broad band width and tolerance to mismatching under conditions of highly fluctuating loading by the material passing by, this being connected with large fluctuations of the radiation wave amplitude in dependence on frequency.
  • the transverse radiator device comprises a group of discrete radiator elements in the form of short circuited E-sector horns the dimension of which in the Wave propagation direction is smaller than two wavelengths in free space, and which are arranged for being excited into H oscillation, the horns being ararnged in a row with their broad sides extending perpendicularly to the polarisation direction, the polarisation direction in the aperture of all horns being the same. Accordingly, in longitudinal direction of the transverse radiator device, a homogeneous amplitude distribution is achieved, so that the material which moves past the aperture perpendicularly to the longitudinal direction of the radiators is uniformly heated.
  • a wave guide preferably a coaxial line
  • Coupling loops of the radiator elements, which excite the rectangular wave guide or the E-sector born into H oscillation can extend through these openings into the coaxial line and can be capacitively or conductively coupled there by known means.
  • the transverse radiator has a series of other advantages compared with known radiators.
  • the wave amplitude course has a considerably lower frequency dependence, so that it satisfies an important requirement, namely that generators with any frequency lying within a predetermined frequency band can be connected, without the energy distribution fluctuating essentially.
  • any desired radiator length can be produced by adding further radiator elements on the building block principle.
  • the structural height of the radiator device of the invention is small.
  • the generator can be directly connected with the feed line, and simple compensation can be achieved with compensation means.
  • FIG. 1 is a perspective view of a conventional E-sector horn
  • FIG. 2 shows the wave amplitude course for the aperture of the horn of FIG. 1, with vertical polarisation
  • FIG. 3 is a perspective view of an embodiment of the transverse radiator according to the invention.
  • FIG. 4 shows the wave amplitude course for the aperture of the radiator of FIG. 3, with vertical polarisation of the radiator elements
  • FIG. 5 is a longitudinal section of the transverse radiator of FIG. 3;
  • FIG. 6 is a fragmentary sectional view of the coupling system of the radiator of FIG. 5.
  • FIG. 1 a conventional E-sector horn 1 is illustrated which is excited from a coupling opening 2 by a coupling loop 3. If this horn is excited with an H wave 4, then the amplitude distribution 5, 6, is produced, which is indicated by the shaded surfaces in FIG. 2, for the aperture 7 with the rectangular sides a and b of this E-sector horn 1. In the vertical plane 5 the distribution is homogeneous and in the horizontal plane 6 the distribution is sinusoidal.
  • FIG. 3 which shows an embodiment of the transverse radiator according to the invention, the serial arrangement of a plurality of E-sector horns (or open rectangular hollow guides) 8, 9, 10, 11, 12 and the excitation from a coaxial feed line 13 by known coupling elements 14, 15 is illustrated.
  • the coupling loops in successive radiator elements are displaced through relative to each other in order that the polarisation of all radiator elements has the same direction. If the individual radiator elements 8 to 12 are excited in the same phase by. coupling elements 14, 15 having the abovementioned 180 displacement, then an amplitude distribution 16, 17, is given as shown in FIG. 4, for the aperture 18 having the rectangular sides a and b, this being indicated by the shaded surfaces.
  • FIG. 5 the construction of the transverse radiator and the generator 19 connected therewith, with the compensation line 20 disposed therebetween can be seen.
  • a part of the wave coming from the generator is coupled from the coupling pin 21 into the E-sector horn 22, which is excited into H oscillation by the inductive loop 23.
  • the radiation wave is transferred from the aperture 18 to the goods 24 being heated.
  • the remaining part of the wave is further propagated to the next coupling opening 25, where again a part of the wave is coupled out, the coupling loop 26 in the E-sector horn 27 being displaced through 180 relative to the first coupling 23.
  • the coaxial line is terminated with a short circuit 28, which is spaced by one quarter or one half wavelength from the last coupling opening 29.
  • the coupling is so adjusted that the amplitude distribution 16, 17 over the aperture 18 of the transverse radiator is homogeneous.
  • the necessary penetration depth of the coupling pin 21 into the coaxial line 13 can be adjusted by the screw connection 30 illustrated in FIG. 6.
  • the coaxial line has the same cross section as the output coupling of the microwave generator 19' connected thereto.
  • known compensation means for example pins or plates, are provided between the generator and the transverse radiator.
  • Microwave heating apparatus comprising,
  • means defining a contiguous array of hollow conducting waveguides dimensioned to propagate the H mode between an input surface and an output surface separated from the output surface by a distance that is less than two wavelengths of exciting microwave energy in air,
  • said waveguides being open at said output surface
  • Microwave heating apparatus in accordance with claim 1 wherein said input and output surfaces are parallel planes.
  • Microwave heating apparatus in accordance with claim 2 wherein said hollow conducting waveguides are rectangular.
  • Microwave heating apparatus in accordance with claim 2 wherein said hollow conducting waveguides are square.
  • Microwave heating apparatus in accordance with claim 1 wherein said input waveguide is a coaxial transmission line having its outer conductor adjacent to said input surface.
  • Microwave heating apparatus in accordance with claim 5 wherein said means for coupling comprises coupling loops including a conducting link extending from the coaxial transmission line inner conductor to a conducting wall common to a contiguous waveguide whereby alternate common conducting walls have two of such conducting links while the remaining common conducting walls have none to thereby cophasally and codirectionally excite the mouths of each hollow conducting waveguide with said exciting microwave heating energy.
  • Apparatus for heating non-metallic materials in an electromagnet radiation field comprising,
  • a plurality of side-by-side waveguide radiators having individual open ends which together form a common elongated aperture, common feed waveguide coupled to said plurality of waveguides for coupling energy to said plurality of waveguides through coupling holes in each, said common feed waveguide being arranged for establishing standing wave conditions, said coupling holes being spaced substantially a half wavelength apart in said common feed waveguide,

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Waveguide Aerials (AREA)
US556735A 1965-06-18 1966-06-10 Transverse radiator device for heating non-metallic materials in an electromagnetic radiation field Expired - Lifetime US3495062A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEA0049508 1965-06-18

Publications (1)

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US3495062A true US3495062A (en) 1970-02-10

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US556735A Expired - Lifetime US3495062A (en) 1965-06-18 1966-06-10 Transverse radiator device for heating non-metallic materials in an electromagnetic radiation field

Country Status (6)

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US (1) US3495062A (en, 2012)
CH (1) CH462347A (en, 2012)
DE (1) DE1565266A1 (en, 2012)
GB (1) GB1146509A (en, 2012)
NL (1) NL6607732A (en, 2012)
SE (1) SE327029B (en, 2012)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3573835A (en) * 1969-01-14 1971-04-06 Hughes Aircraft Co Impedance matched open-ended waveguide array
US3999026A (en) * 1974-02-22 1976-12-21 Stiftelsen Institutet For Mikrovagsteknik Vid Teknishka Hogskolan I Stockholm Heating device fed with microwave energy
US4463430A (en) * 1981-08-31 1984-07-31 Beta Corporation Microprocessor based pellet mill control
EP3121900A4 (en) * 2014-04-30 2017-03-22 Huawei Technologies Co. Ltd. Power feeder
AU2017201477B2 (en) * 2012-03-14 2019-01-31 Microwave Materials Technologies, Inc. Enhanced microwave heating systems and methods of using the same
US10798790B2 (en) 2012-03-14 2020-10-06 Microwave Materials Technologies, Inc. Enhanced microwave system utilizing tilted launchers
US10966293B2 (en) 2017-04-17 2021-03-30 915 Labs, LLC Microwave-assisted sterilization and pasteurization system using synergistic packaging, carrier and launcher configurations
US11032879B2 (en) 2017-03-15 2021-06-08 915 Labs, Inc. Energy control elements for improved microwave heating of packaged articles
US11129243B2 (en) 2017-03-15 2021-09-21 915 Labs, Inc. Multi-pass microwave heating system

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2667198B1 (fr) * 1990-09-21 1993-08-13 Applic Rech Electro Ste Reseau directif pour radiocommunications, a elements rayonnants adjacents et ensemble de tels reseaux directifs.
JP5816820B2 (ja) * 2012-08-29 2015-11-18 パナソニックＩｐマネジメント株式会社 マイクロ波加熱装置

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2349942A (en) * 1939-08-22 1944-05-30 Dallenbach Walter Hollow space radiator
US2398095A (en) * 1940-08-31 1946-04-09 Rca Corp Electromagnetic horn radiator
US2628311A (en) * 1948-11-04 1953-02-10 Rca Corp Multiple slot antenna
US2689303A (en) * 1946-05-24 1954-09-14 Us Sec War Antenna array
US2718592A (en) * 1951-04-28 1955-09-20 Bell Telephone Labor Inc Antenna
US2903695A (en) * 1954-01-20 1959-09-08 Hugh W Jamieson Impedance matching feeder for an antenna array
US2908002A (en) * 1955-06-08 1959-10-06 Hughes Aircraft Co Electromagnetic reflector
US3263052A (en) * 1963-09-11 1966-07-26 Cryodry Corp Power distribution system for microwave process chambers

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2349942A (en) * 1939-08-22 1944-05-30 Dallenbach Walter Hollow space radiator
US2398095A (en) * 1940-08-31 1946-04-09 Rca Corp Electromagnetic horn radiator
US2689303A (en) * 1946-05-24 1954-09-14 Us Sec War Antenna array
US2628311A (en) * 1948-11-04 1953-02-10 Rca Corp Multiple slot antenna
US2718592A (en) * 1951-04-28 1955-09-20 Bell Telephone Labor Inc Antenna
US2903695A (en) * 1954-01-20 1959-09-08 Hugh W Jamieson Impedance matching feeder for an antenna array
US2908002A (en) * 1955-06-08 1959-10-06 Hughes Aircraft Co Electromagnetic reflector
US3263052A (en) * 1963-09-11 1966-07-26 Cryodry Corp Power distribution system for microwave process chambers

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3573835A (en) * 1969-01-14 1971-04-06 Hughes Aircraft Co Impedance matched open-ended waveguide array
US3999026A (en) * 1974-02-22 1976-12-21 Stiftelsen Institutet For Mikrovagsteknik Vid Teknishka Hogskolan I Stockholm Heating device fed with microwave energy
US4463430A (en) * 1981-08-31 1984-07-31 Beta Corporation Microprocessor based pellet mill control
AU2017201477B2 (en) * 2012-03-14 2019-01-31 Microwave Materials Technologies, Inc. Enhanced microwave heating systems and methods of using the same
US10798790B2 (en) 2012-03-14 2020-10-06 Microwave Materials Technologies, Inc. Enhanced microwave system utilizing tilted launchers
EP3121900A4 (en) * 2014-04-30 2017-03-22 Huawei Technologies Co. Ltd. Power feeder
US11032879B2 (en) 2017-03-15 2021-06-08 915 Labs, Inc. Energy control elements for improved microwave heating of packaged articles
US11129243B2 (en) 2017-03-15 2021-09-21 915 Labs, Inc. Multi-pass microwave heating system
US12309905B2 (en) 2017-03-15 2025-05-20 915 Labs, Inc. Energy control elements for improved microwave heating of packaged articles
US10966293B2 (en) 2017-04-17 2021-03-30 915 Labs, LLC Microwave-assisted sterilization and pasteurization system using synergistic packaging, carrier and launcher configurations

Also Published As

Publication number Publication date
SE327029B (en, 2012) 1970-08-10
NL6607732A (en, 2012) 1966-12-19
CH462347A (de) 1968-09-15
DE1565266A1 (de) 1970-02-05
GB1146509A (en) 1969-03-26

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