US4453108A
Expired / Lapsed
US
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Device for generating RF energy from electromagnetic radiation of another form such as light
Assignee: Rice University
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Filing: 1981-12-10
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Granted: 1984-06-05
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Expires: 2001-12-10
Abstract
Abstract A device for generating RF energy from electromagnetic radiation of another form, such as light, includes an emitter responsive to the electromagnetic radiation for producing a beam of charged particles, an electrode spaced from the emitter to define a path for the charged particles, and a resonant structure for supporting RF oscillations and disposed with respect to the path to enable energy transfer between the charged particles and an RF field associated with the RF oscillations. When biased, the devices operate in a multi-pass mode, wherein the charged particles undergo multiple oscillations while remaining in phase with the RF field. When unbiased, the devices operate in a half-cycle mode to produce RF oscillations with no externally applied input power other than the electromagnetic radiation.
Inventors
- 👤 John W. Freeman, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:22
CPC Classifications
H; H01; H01J; H01J25/00; H01J25/02; H01J25/22; H01J25/30
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
171 words
A device for generating RF energy from electromagnetic radiation comprising emitter means responsive to the electromagnetic radiation for producing a beam of charged particles, an electrode spaced from the emitter means, the emitter means and the electrode defining a path therebetween along which the charged particles move, the path having a predetermined path length and the emitter means having a dimension transverse to the path that is greater than the path length such that the beam of charged particles has a transverse dimension greater than the path length, and a resonant structure for supporting RF oscillations, the resonant structure being located with respect to the path so as to define a plurality of RF field regions along the path and so as to enable continuous energy transfer in each region from the charged particles to an RF field associated with the RF oscillations, the resonant structure comprising a pair of grids spaced along said path and with both grids having a positive bias relative to said emitter means and said electrode.
Claim 2
Independent Claim
171 words
A device for generating RF energy from electromagnetic radiation comprising emitter means responsive to the electromagnetic radiation for producing a beam of charged particles, an electrode spaced from the emitter means, the emitter means and the electrode defining a path therebetween along which the charged particles move, the path having a predetermined path length and the emitter means having a dimension transverse to the path that is greater than the path length such that the beam of charged particles has a transverse dimension greater than the path length, and a resonant structure for supporting RF oscillations, the resonant structure being located with respect to the path so as to define a plurality of RF field regions along the path and so as to enable continuous energy transfer in each region from the charged particles to an RF field associated with the RF oscillations, the resonant structure comprising a pair of grids spaced along said path and with both grids having a positive bias relative to said emitter means and said electrode.
Claim 3
Dependent Claim
36 words
The device of claim 1, wherein the path is positioned such that it is substantially totally within the RF field regions so as to enable energy transfer to the RF field over substantially the entire path.
Claim 4
Dependent Claim
24 words
The device of claim 1, wherein the ratio of the surface area of the emitter means to the path length is at least 2:1.
Claim 5
Dependent Claim
16 words
The device of claim 1, wherein the beam of charged particles comprises low energy charged particles.
Claim 6
Dependent Claim
18 words
The device of claim 4, wherein the energy of the charged particles is less than about 100 eV.
Claim 7
Dependent Claim
20 words
The device of claim 5, wherein the energy of the charged particles is of the order of a few eV.
Claim 8
Dependent Claim
60 words
The device of claim 1, wherein the bias sets the transit time of the charged particles along the path such that selected charged particles transfer energy to the RF field to reinforce the RF oscillations and such that charged particles that do not have proper phase relationship to the RF field to transfer energy thereto are eliminated from the beam.
Claim 9
Dependent Claim
36 words
The device of claim 7, wherein the bias is set to cause the selected charged particles to make successive passes along the path while remaining substantially in phase with the RF field to transfer energy thereto.
Claim 10
Dependent Claim
17 words
The device of claim 8, wherein the electrode is a reflector electrode for reflecting the charged particles.
Claim 11
Dependent Claim
14 words
The device of claim 9, wherein the bias is less than about 100 volts.
Claim 12
Dependent Claim
38 words
The device of claim 9, wherein the bias sets the transit time of the charged particles along the path such that the transit time is an integral or near integral multiple of the period of the RF oscillations.
Claim 13
Dependent Claim
25 words
The device of claim 9, wherein the grids are grounded and the emitter means and the electrode are biased negative with respect to ground potential.
Claim 14
Dependent Claim
9 words
The device of claim 9, including a further grid.
Claim 15
Dependent Claim
18 words
The device of claim 9, wherein the resonant structure includes an inductor connected to the pair of grids.
Claim 16
Independent Claim
183 words
A device for generating RF energy from electromagnetic radiation comprising emitter means responsive to the electromagnetic radiation for producing a beam of charged particles, an electrode spaced from the emitter means, the emitter means and the electrode defining a path therebetween along which the charged particles move, and a resonant structure for supporting RF oscillations disposed between the emitter means and the electrode and positioned with respect to the path so as to enable continuous energy transfer from the charged particles to an RF field associated with the RF oscillations over a large portion of the path, the resonant structure comprising a pair of grids spaced along said path and with both grids having a positive bias relative to said emitter means and said electrode, and wherein the device is free of beam focusing structure such that the beam of charged particles moving along the path is unfocused, the dimensions of the emitter means being such as to provide a beam having a substantial cross-sectional dimension and the spacing between the electrode and the emitter means being such as to minimize beam spreading.
Claim 17
Independent Claim
183 words
A device for generating RF energy from electromagnetic radiation comprising emitter means responsive to the electromagnetic radiation for producing a beam of charged particles, an electrode spaced from the emitter means, the emitter means and the electrode defining a path therebetween along which the charged particles move, and a resonant structure for supporting RF oscillations disposed between the emitter means and the electrode and positioned with respect to the path so as to enable continuous energy transfer from the charged particles to an RF field associated with the RF oscillations over a large portion of the path, the resonant structure comprising a pair of grids spaced along said path and with both grids having a positive bias relative to said emitter means and said electrode, and wherein the device is free of beam focusing structure such that the beam of charged particles moving along the path is unfocused, the dimensions of the emitter means being such as to provide a beam having a substantial cross-sectional dimension and the spacing between the electrode and the emitter means being such as to minimize beam spreading.
Claim 18
Dependent Claim
40 words
The device of claim 15, wherein the spacing between the emitter means and the electrode is set such that the charged particles are within the RF field for substantially their entire transit time between the emitter means and the electrode.
Claim 19
Dependent Claim
40 words
The device of claim 15, wherein the emitter means, the resonant structure, and the electrode define successive regions along the path and are interconnected such that the charged particles transfer energy to the RF field in each of said regions.
Claim 20
Dependent Claim
35 words
The device of claim 15, wherein the bias is set to cause charged particles to make multiple passes along the path while remaining substantially in phase with the RF field to continuously transfer energy thereto.
Claim 21
Dependent Claim
52 words
The device of claim 18, wherein the bias is set such that the cycle time required for the charged particles to move along the path from the emitter means to the electrode and back to the emitter means is an integral or near integral multiple of the period of the RF oscillations.
Claim 22
Dependent Claim
61 words
The device of claim 15, wherein the bias sets the transit time of the charged particles along the path such that selected charged particles transfer energy to the RF field to reinforce the RF oscillations and such that charged particles that do not have a proper phase relationship to the RF field to transfer energy thereto are eliminated from the beam.
Claim 23
Dependent Claim
20 words
The device of claim 15, wherein the beam of charged particles moving along said path comprises low energy charged particles.
Claim 24
Independent Claim
134 words
A device for generating RF energy from electromagnetic radiation comprising emitter means responsive to the electromagnetic radiation impinging upon the emitter means for producing a beam of charged particles, an electrode spaced from the emitter means, the emitter means and the electrode defining a path therebetween along which the charged particles move, the charged particles moving along said path primarily as a result of the kinetic energy imparted to the charged particles by the electromagnetic radiation that produces the charged particles, and a resonant structure disposed between the emitter means and the electrode for supporting RF oscillations, the resonant structure being located with respect to the beam of charged particles to enable energy transfer from charged particles to an RF field associated with the RF oscillations, said device being free of externally applied voltages.
Claim 25
Independent Claim
134 words
A device for generating RF energy from electromagnetic radiation comprising emitter means responsive to the electromagnetic radiation impinging upon the emitter means for producing a beam of charged particles, an electrode spaced from the emitter means, the emitter means and the electrode defining a path therebetween along which the charged particles move, the charged particles moving along said path primarily as a result of the kinetic energy imparted to the charged particles by the electromagnetic radiation that produces the charged particles, and a resonant structure disposed between the emitter means and the electrode for supporting RF oscillations, the resonant structure being located with respect to the beam of charged particles to enable energy transfer from charged particles to an RF field associated with the RF oscillations, said device being free of externally applied voltages.
Claim 26
Dependent Claim
20 words
The device of claim 22, wherein the charged particles have low energies of the order of a few electron volts.
Claim 27
Dependent Claim
34 words
The device of claim 22, wherein a passive electrical element is connected between the electrode and the resonant structure to provide a current path that biases the electrode with respect to the resonant structure.
Claim 28
Dependent Claim
30 words
The device of claim 22, wherein the dimensions of said device are such that the charged particles that transfer energy to said RF field are in phase with said field.
Claim 29
Dependent Claim
20 words
The device of claim 22, wherein the cross-dimensions of said beam are substantially greater than the length of said path.
Claim 30
Dependent Claim
23 words
The device of claim 22, wherein said resonant structure comprises a pair of grids spaced along said path and interconnected by an inductance.
Claim 31
Dependent Claim
18 words
The device of claim 27, wherein said inductance has a tap connected to said electrode by a resistance.
Claim 32
Independent Claim
144 words
A device for generating RF energy from electromagnetic radiation comprising emitter means responsive to the electromagnetic radiation for producing a beam of low energy charged particles, a reflector electrode spaced from the emitter means, the emitter means and the electrode defining a path therebetween along which the charged particles move, a resonant structure for supporting RF oscillations disposed between the emitter means and the electrode and positioned with respect to the path to enable energy transfer between charged particles and an RF field associated with the RF oscillations, the resonant structure comprising a pair of grids spaced along said path and with both grids having a positive bias relative to said emitter means and said electrode, said bias being set to cause charged particles to remain substantially in phase with the RF field as they move along the path to continually transfer energy thereto.
Claim 33
Independent Claim
144 words
A device for generating RF energy from electromagnetic radiation comprising emitter means responsive to the electromagnetic radiation for producing a beam of low energy charged particles, a reflector electrode spaced from the emitter means, the emitter means and the electrode defining a path therebetween along which the charged particles move, a resonant structure for supporting RF oscillations disposed between the emitter means and the electrode and positioned with respect to the path to enable energy transfer between charged particles and an RF field associated with the RF oscillations, the resonant structure comprising a pair of grids spaced along said path and with both grids having a positive bias relative to said emitter means and said electrode, said bias being set to cause charged particles to remain substantially in phase with the RF field as they move along the path to continually transfer energy thereto.
Claim 34
Dependent Claim
32 words
The device of claim 29, wherein the bias is set to cause the charged particles to make multiple passes along the path while remaining continuously substantially in phase with the RF field.
Claim 35
Dependent Claim
35 words
The device of claim 30, wherein the charged particles have energies in the range of a few electron volts to approximately 100 electron volts, and the low voltage means is about 100 volts or less.
Claim 36
Dependent Claim
56 words
The device of claim 29 the transit time of the charged particles along the path such that selected charged particles transfer energy to the RF field to reinforce the RF oscillations and such that charged particles that do not have a proper phase relationship to the field to transfer energy thereto are eliminated from the beam.
Claim 37
Dependent Claim
27 words
The device of claim 29, wherein the path of the charged particles is substantially totally within the RF field, and the beam of charged particles is unfocused.
Claim 38
Dependent Claim
27 words
The device of claim 1, 17, 25 or 29, wherein the electromagnetic radiation comprises light, the emitter means comprises a photocathode, and the charged particles comprise electrons.
Claim 39
Dependent Claim
39 words
The device of claim 34 further comprising a housing for enclosing the photocathode, and wherein the photocathode comprises a layer of photoemissive material deposited on the inside surface of a window of the housing through which the light passes.
Claim 40
Dependent Claim
58 words
The device of claim 34 further comprising a housing for enclosing the photocathode, and the electrode, and wherein the photocathode comprises a layer of photoemissive material deposited on a metallic member within the housing, and the electrode comprises a thin metallic layer deposited on the inside surface of a window of the housing through which the light passes.
Claim 41
Dependent Claim
13 words
The device of claim 34, wherein the resonant structure comprises a resonant cavity.
Claim 42
Independent Claim
103 words
A method of generating RF energy from electromagnetic radiation comprising producing from the electromagnetic radiation an unfocused beam of low energy charged particles that move along a predetermined path, locating the path in an RF field associated with RF oscillations in a resonant structure, the resonant structure comprising a pair of grids spaced along said path and with both grids having a positive bias relative to said emitter means and said electrode, and such that the path is substantially entirely without the RF field to enable continuous energy transfer to the RF field from the charged particles as they move along the path.
Claim 43
Independent Claim
103 words
A method of generating RF energy from electromagnetic radiation comprising producing from the electromagnetic radiation an unfocused beam of low energy charged particles that move along a predetermined path, locating the path in an RF field associated with RF oscillations in a resonant structure, the resonant structure comprising a pair of grids spaced along said path and with both grids having a positive bias relative to said emitter means and said electrode, and such that the path is substantially entirely without the RF field to enable continuous energy transfer to the RF field from the charged particles as they move along the path.
Claim 44
Dependent Claim
37 words
The method of claim 38 further comprising setting the bias such that charged particles that do not have a proper phase relationship with respect to the RF field to transfer energy thereto are eliminated from the beam.
Claim 45
Dependent Claim
35 words
The method of claim 38 further comprising setting the bias to cause charged particles to make multiple passes along the path while remaining substantially in phase with the RF field to continually transfer energy thereto.
Claim 46
Dependent Claim
36 words
The method of claim 38 further comprising setting the bias such that the transit time of the charged particles along the path is an integral or near integral multiple of the period of the RF oscillations.
Claim 47
Dependent Claim
23 words
The device of claim 17, wherein the RF field in each region is in anti-phase with the RF field in a neighboring region.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-05 | 1987-12-05 | 1988-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-05 | 1991-12-05 | 1992-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-05 | 1995-12-05 | 1996-06-05 | $7700.00 | Window Closed / Lapsed |