US3581038A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave applicator employing a broadside radiator in a conductive enclosure
Assignee: Varian Medical Systems Inc
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Filing: 1969-05-02
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Granted: 1971-05-25
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Expires: 1989-05-02
Abstract
Abstract A microwave applicator for treating material with microwave energy is disclosed. The applicator includes a relatively large conductive enclosure containing a large broadside microwave radiating antenna disposed for directing the radiated microwave energy onto the load of lossy material for treating same. The applicator is particularly useful for treating relatively large amounts of lossy material.
Inventors
- 👤 Norman H Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:53
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/80
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
138 words
In an electromagnetic energy applicator apparatus, means forming an electromagnetic energy shield for confining the energy and for containing lossy material to be treated with such energy, an electromagnetic radiative structure disposed for radiating electromagnetic energy directly onto the material to be treated within said shield, said structure comprising a pair of transversely spaced generally parallel elongated hollow waveguides, each of which is provided along its length with a generally resonant array of spaced radiative elements arranged to be excited by electromagnetic energy substantially in phase with each other at the operating frequency of the applicator to radiate a uniform pattern of radiation from each of said waveguides for uniform treatment of the lossy material, a source of electromagnetic energy, and means for feeding approximately equal amounts of electromagnetic energy from said source to each of said waveguides.
Claim 2
Dependent Claim
138 words
In an electromagnetic energy applicator apparatus, means forming an electromagnetic energy shield for confining the energy and for containing lossy material to be treated with such energy, an electromagnetic radiative structure disposed for radiating electromagnetic energy directly onto the material to be treated within said shield, said structure comprising a pair of transversely spaced generally parallel elongated hollow waveguides, each of which is provided along its length with a generally resonant array of spaced radiative elements arranged to be excited by electromagnetic energy substantially in phase with each other at the operating frequency of the applicator to radiate a uniform pattern of radiation from each of said waveguides for uniform treatment of the lossy material, a source of electromagnetic energy, and means for feeding approximately equal amounts of electromagnetic energy from said source to each of said waveguides.
Claim 3
Dependent Claim
26 words
The apparatus of claim 1 wherein said radiative elements for each of said waveguides comprise an array of slots communicating through a wall of said waveguide.
Claim 4
Dependent Claim
36 words
The apparatus of claim 2 wherein said slots are spaced apart along the length of said waveguide by approximately an integral number of half guide wavelengths within said waveguide at the operating frequency of the applicator.
Claim 5
Dependent Claim
47 words
The apparatus of claim 3 wherein each of said waveguides is of rectangular cross section having a pair of broad and a pair of narrow walls, and adjacent slots are oppositely inclined relative to the transverse plane of said waveguide to obtain in-phase excitation of adjacent slots.
Claim 6
Dependent Claim
41 words
The apparatus of claim 2 including means for short circuiting both ends of each of said hollow waveguide and said means for feeding electromagnetic energy into said hollow waveguides does so at a point generally midway along the length of each.
Claim 7
Dependent Claim
90 words
The apparatus of claim 5 wherein said centrally disposed microwave feed includes a short slot hybrid coupler having one input port to be connected to said source of electromagnetic energy and having a pair of output ports, a pair of waveguides transversely directed of said slotted parallel waveguides for interconnecting each of said output ports of said hybrid coupler and the central feed point of each of said slotted waveguides for feeding approximately equal amounts energy to each of said parallel slotted waveguides from said common source of electromagnetic energy.
Claim 8
Dependent Claim
31 words
The apparatus of claim 6 including a movable wave reflective element coupled to a fourth port of said hybrid coupler for balancing the power flow to said parallel slotted waveguide radiators.
Claim 9
Dependent Claim
72 words
The apparatus of claim 6 wherein said pair of transversely directed waveguides are coupled through the broad walls of said slotted waveguides to form series T connections to each of said parallel waveguides, and wherein the impedance of each of said slot radiative elements is approximately nZo/4, wherein n is the number of radiative slots in each parallel slotted waveguide and Zo is the characteristic impedance of each of said parallel waveguides.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |