US3622732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave applicator with distributed feed to a resonator
Assignee: Varian Medical Systems Inc
•
Filing: 1970-01-14
•
Granted: 1971-11-23
•
Expires: 1990-01-14
Abstract
Abstract A microwave applicator is disclosed which employs an elongated hollow resonator dimensioned to be cut off for the dominant waveguide mode at the frequency of the applicator. A hollow waveguide feed extends along and adjacent the resonator and includes a distributed coupling means providing a distributed wave energy feed path from the waveguide to the resonator. The distributed coupling means is arranged for exciting a transverse TEM mode in the resonator to produce standing wave microwave electric fields in the plane of a relatively thin elongated treatment zone within the resonator. The resonator includes a pair of elongated openings in registration with the treatment zone for passage of thin webs of material through the treatment zone. The distributed coupling means is preferably arranged to provide an increasing coefficient of coupling taken in the direction of power flow through the feed waveguide. Thus, the power is distributed to the resonator uniformly.
Inventors
- 👤 Norman H Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:24
CPC Classifications
H; H01; H01P; H01P5/00; H01P5/12; H01P5/16; H05; H05B; H05B6/00; H05B6/64; H05B6/78
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
165 words
In a microwave applicator for treating material with microwave energy, an elongated hollow resonator for applying standing wave microwave electric fields to a relatively thin elongated treatment zone which extends longitudinally of said elongated resonator, an elongated waveguide means extending Longitudinally of said elongated resonator for conveying microwave power therealong, coupling means distributed along the length of said resonator for providing distributed wave energy communication between said waveguide and said resonator for distributing microwave power from said waveguide to said resonator along the length of said resonator, the improvement wherein, said resonator means is dimensioned to be cut off for the dominant longitudinal waveguide mode therein at the operating frequency of the applicator, and wherein said coupling means is arranged for exciting a resonant TEM mode in said resonator to the exclusion of exciting other possible modes of oscillation, and wherein the reference direction for the TEM mode is a direction normal to the longitudinal axis of said resonator, whereby improved mode control is obtained.
Claim 2
Dependent Claim
165 words
In a microwave applicator for treating material with microwave energy, an elongated hollow resonator for applying standing wave microwave electric fields to a relatively thin elongated treatment zone which extends longitudinally of said elongated resonator, an elongated waveguide means extending Longitudinally of said elongated resonator for conveying microwave power therealong, coupling means distributed along the length of said resonator for providing distributed wave energy communication between said waveguide and said resonator for distributing microwave power from said waveguide to said resonator along the length of said resonator, the improvement wherein, said resonator means is dimensioned to be cut off for the dominant longitudinal waveguide mode therein at the operating frequency of the applicator, and wherein said coupling means is arranged for exciting a resonant TEM mode in said resonator to the exclusion of exciting other possible modes of oscillation, and wherein the reference direction for the TEM mode is a direction normal to the longitudinal axis of said resonator, whereby improved mode control is obtained.
Claim 3
Dependent Claim
35 words
The apparatus of claim 1 wherein said resonator includes a pair of ports disposed in opposite sidewalls of said hollow resonator in alignment with the treatment zone for passage therethrough of material to be treated.
Claim 4
Dependent Claim
71 words
The apparatus of claim 2 wherein said hollow resonator means is of generally rectangular transverse cross section having a pair of broad walls and a pair of narrow sidewalls, said pair of ports being disposed in said broad walls and being elongated in the longitudinal direction of said cavity, and the width of said broad walls is equal to or less than one-half the free space wavelength at the operating frequency.
Claim 5
Dependent Claim
35 words
The apparatus of claim 1 including a pair of wave energy absorbing means disposed within said elongated resonator at opposite ends thereof to obtain a nearly uniform microwave field near the ends of said resonator.
Claim 6
Dependent Claim
33 words
The apparatus of claim 1 wherein said waveguide means and said resonator means share a common wall, and wherein said coupling means includes an array of coupling holes communicating through said common wall.
Claim 7
Dependent Claim
47 words
The apparatus of claim 5 wherein said waveguide and said resonator are of rectangular transverse section each having broad walls interconnected by narrow walls, and wherein the width of said broad walls of said resonator is less than the width of said broad walls of said waveguide.
Claim 8
Dependent Claim
24 words
The apparatus of claim 6 wherein said waveguide is tapered with decreasing width taken in the direction of power flow therealong to said resonator.
Claim 9
Dependent Claim
19 words
The apparatus of claim 5 wherein said common wall is a broad wall of said resonator and said waveguide.
Claim 10
Dependent Claim
19 words
The apparatus of claim 5 wherein said common wall is a narrow wall of said resonator and said waveguide.
Claim 11
Dependent Claim
42 words
The apparatus of claim 1 in which said resonator has two pairs of opposed elongated walls and the width of each wall of one of said pairs is equal to or less than one-half the free space wavelength at the operating frequency.
Claim 12
Dependent Claim
58 words
A microwave applicator for treating material with microwave energy comprising, a waveguide, wall means forming a cavity adjacent one side of said waveguide, means for coupling wave energy from said waveguide to said cavity, port means in said waveguide and said cavity walls through which material to be treated can pass through both said waveguide and said cavity.
Claim 13
Dependent Claim
58 words
A microwave applicator for treating material with microwave energy comprising, a waveguide, wall means forming a cavity adjacent one side of said waveguide, means for coupling wave energy from said waveguide to said cavity, port means in said waveguide and said cavity walls through which material to be treated can pass through both said waveguide and said cavity.
Claim 14
Dependent Claim
69 words
A microwave applicator as claimed in claim 11 in which said waveguide and cavity have a common wall, said port means includes an elongated slot in said common wall, said coupling means comprises coupling holes in said common wall spaced along opposite sides of said slot with the coupling holes on one side of the slot being located between the coupling holes on the other side of the slot.
References Cited (Backward Citations)
US3439143A
Cited
US3507050A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |