US3560694A — Microwave applicator employing flat multimode cav…

Claim 1

Independent Claim 293 words

In an electromagnetic applicator, a multimode cavity resonator having openings on opposite sides thereof for passing material to be treated with electromagnetic energy through a thin wide treatment zone contained within said cavity, said cavity having a pair of parallel broad walls closed at their side edges by narrow walls with said openings disposed in a pair of said narrow walls and aligned in the plane of the thin wide treatment zone, means for exciting said cavity with standing waves of electromagnetic of such a class of resonant modes that the electric field vector in the treatment zone is generally parallel to said broad walls of said cavity and lies generally within the plane of the thin wide treatment zone, the spacing between the pair of broad walls of said cavity being at least equal to onehalf wavelength and less than one wavelength at the operating frequency of said cavity whereby certain undesired classes of modes are not supported, and being dimensioned to have sufficient length and width to support both the TEl,m,n and TMl,m,n classes of modes of oscillation in said cavity at the frequency of operation where l is 1 and the range of both m and n is greater than 10, said means for exciting said cavity resonator with microwave energy including a hollow rectangular waveguide opening into said cavity at a narrow wall of said cavity, said rectangular waveguide having a pair of broad walls and a pair of narrow sidewalls with the planes of the broad walls of said waveguide being generally perpendicular to the planes of the broad walls of said cavity resonator to preferentially excite in said cavity modes of oscillation having their electric field vectors parallel to the cavity broad walls at the treatment zone.

Claim 2

Dependent Claim 293 words

In an electromagnetic applicator, a multimode cavity resonator having openings on opposite sides thereof for passing material to be treated with electromagnetic energy through a thin wide treatment zone contained within said cavity, said cavity having a pair of parallel broad walls closed at their side edges by narrow walls with said openings disposed in a pair of said narrow walls and aligned in the plane of the thin wide treatment zone, means for exciting said cavity with standing waves of electromagnetic of such a class of resonant modes that the electric field vector in the treatment zone is generally parallel to said broad walls of said cavity and lies generally within the plane of the thin wide treatment zone, the spacing between the pair of broad walls of said cavity being at least equal to onehalf wavelength and less than one wavelength at the operating frequency of said cavity whereby certain undesired classes of modes are not supported, and being dimensioned to have sufficient length and width to support both the TEl,m,n and TMl,m,n classes of modes of oscillation in said cavity at the frequency of operation where l is 1 and the range of both m and n is greater than 10, said means for exciting said cavity resonator with microwave energy including a hollow rectangular waveguide opening into said cavity at a narrow wall of said cavity, said rectangular waveguide having a pair of broad walls and a pair of narrow sidewalls with the planes of the broad walls of said waveguide being generally perpendicular to the planes of the broad walls of said cavity resonator to preferentially excite in said cavity modes of oscillation having their electric field vectors parallel to the cavity broad walls at the treatment zone.

Claim 3

Dependent Claim 44 words

The apparatus of claim 1 including duct means for directing gas into and out of said cavity, said duct means being disposed at said pair of narrow sidewalls which have the openings therein for passage of the material to be treated through the resonator.

Claim 4

Dependent Claim 30 words

The apparatus of claim 2 wherein said duct means includes a plurality of adjacent conductive passageways having transverse inside dimensions below cutoff at the operating frequency of said cavity resonator.

Claim 5

Dependent Claim 53 words

The apparatus of claim 3 wherein the ducts are arranged to direct a pair of gas streams through said cavity resonator on opposite sides of said treatment zone, with the direction of the gas streams being generally parallel or antiparallel to the direction of movement of the material being treated through said resonator.

Claim 6

Dependent Claim 21 words

The apparatus of claim 1 wherein said waveguide opens into said cavity substantially at one of the corners of said cavity.

Claim 7

Dependent Claim 69 words

The apparatus of claim 1 wherein said cavity resonator comprises two similar half portions joined together along a joint formed in and disposed intermediate the height of two narrow sidewalls which extend generally in the direction of movement of the material to be treated through said resonator, and means forming a microwave attenuator structure disposed in said joint to suppress undesired classes of modes of oscillation in said cavity.

Claim 8

Dependent Claim 38 words

The apparatus of claim 1 wherein means forming an attenuator structure are disposed in said openings in said narrow cavity walls for passing material to be treated to suppress undesired classes of modes of oscillation in said cavity.

Claim 9

Dependent Claim 156 words

An electromagnetic applicator comprising an electromagnetic treatment chamber capable of supporting within its interior electromagnetic wave energy and defined by a pair of generally parallel conductive broad walls closed along opposite side edges by narrow conductive sidewalls, the spacing between said pair of broad walls of said cavity being at least equal to one-half wavelength and less than one wavelength at the operating frequency of said electromagnetic wave energy, means for exciting said chamber with electromagnetic energy of a class of modes of oscillation producing electric field vectors in the midplane between and generally parallel to said broad walls, means for supporting at said midplane within said chamber material to be treated with said energy, and lossy mode-damping means extending along each of said sidewalls at said midplane and generally parallel to said broad walls to attenuate any modes within said chamber having at said midplane an electric field vector not parallel to said broad walls.

Claim 10

Dependent Claim 156 words

An electromagnetic applicator comprising an electromagnetic treatment chamber capable of supporting within its interior electromagnetic wave energy and defined by a pair of generally parallel conductive broad walls closed along opposite side edges by narrow conductive sidewalls, the spacing between said pair of broad walls of said cavity being at least equal to one-half wavelength and less than one wavelength at the operating frequency of said electromagnetic wave energy, means for exciting said chamber with electromagnetic energy of a class of modes of oscillation producing electric field vectors in the midplane between and generally parallel to said broad walls, means for supporting at said midplane within said chamber material to be treated with said energy, and lossy mode-damping means extending along each of said sidewalls at said midplane and generally parallel to said broad walls to attenuate any modes within said chamber having at said midplane an electric field vector not parallel to said broad walls.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1974-02-01	1974-08-03	1975-02-02	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1978-02-01	1978-08-03	1979-02-02	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1982-02-01	1982-08-03	1983-02-02	$7700.00	Window Closed / Lapsed

Microwave applicator employing flat multimode cavity for treating webs

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