CN101770919A - Slow wave line for travelling wave tube - Google Patents
Slow wave line for travelling wave tube Download PDFInfo
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- CN101770919A CN101770919A CN 201010118399 CN201010118399A CN101770919A CN 101770919 A CN101770919 A CN 101770919A CN 201010118399 CN201010118399 CN 201010118399 CN 201010118399 A CN201010118399 A CN 201010118399A CN 101770919 A CN101770919 A CN 101770919A
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Abstract
The invention relates to a slow wave line for a travelling wave tube; a plurality of groups of photonic crystal units are axially arrayed along an electron beam channel of the travelling wave tube, the photonic crystal unit is a hollow structure, the hollow structures of a plurality of the photonic crystal units form the electron beam channel of the travelling wave tube, the foreground materials of the photonic crystal units are arrayed in a two-dimensional periodical way radially, the background material thereof fills the clearances of the foreground materials, the photonic crystal units are fixedly connected together by metal separation plates which are axially arrayed periodically and are separated by the metal separation plates, the foreground materials of the photonic crystal units are alloy permanent magnet material, the background material adopts ferrite permanent magnet material, and the metal separation plate adopts soft magnetic material; the slow wave line has the beneficial effects that: three functions of bunching electron beam, providing slow electromagnetic wave and filtering high order mode electromagnetic waves are realized in the same structure.
Description
Technical field
The invention belongs to the microwave vacuum electronic technology field, specifically, relate to the slow wave line of travelling wave tube.
Background technology
Travelling wave tube is a broadband high-power microwave source device, is widely used in radar communication and Aerospace Satellite communication.Travelling wave tube structural principle schematic diagram as depicted in figs. 1 and 2, this travelling wave tube mainly comprises: electron gun 1, slow wave line 2 (slow wave circuit), beam forming system 3, collector 4, metallic shield shell 5, input waveguide 6 and output waveguide 7.Slow wave line inside has an electron beam channel 8, beam forming system 3 and metallic shield shell 5 are centered around the periphery of slow wave line successively, electron gun 1 and collector 4 lay respectively at the two ends of slow wave line, and input waveguide 6 and output waveguide 7 lay respectively at the two ends of slow wave line and the junction of electron gun 1 and collector 4.Electron gun is provided at ELECTRON OF MOTION bundle in the electron beam channel, and slow wave line is the electromagnetic transmission line, and when electromagnetic wave transmitted in slow wave line, its phase velocity was less than the light velocity, and the electromagnetic wave of this moment is commonly referred to the electromagnetism slow wave; Slow wave line commonly used comprises helix slow wave line, coupled cavity slow wave line and folded waveguide slow wave line.Beam forming system provides necessary magnetic field, so that the direction of motion of electron beam does not change.Collector is the final destination of electron beam.Input waveguide and output waveguide are used for the input and output electromagnetic wave.The effect of metallic shield shell is with space and other spatial separation of electron beam and electromagnetic wave motion, so that high vacuum environment to be provided, avoids electron beam to be subjected to air influence and ionization.
The operation principle of travelling wave tube is, when equating substantially, the kinetic energy of electron beam will be converted into electromagnetic wave energy when electromagnetic phase velocity in the speed of electron beam and the slow wave line (electromagnetic wave angular frequency and electromagnetic wave in slow wave line during unit of transfer's length the ratio of the change amount of phase place).Electron beam is subjected to electromagnetic wave electric field and the action of a magnetic field, its direction of motion must change, in order to make electronics be unlikely to stamp slow wave line and metallic shield shell, need certain magnetically confined electron collection extreme direction campaign, this magnetic field is just provided by beam forming system.
The beam forming system of travelling wave tube can be solenoid, uniform magnetic field or periodic permanent magnet beam forming system.Wherein, the periodic permanent magnet beam forming system is to be made of permanent magnetic material and soft magnetic material, and permanent magnetic material such as SmCo (SmCo) etc. are the one dimension periodic arrangement, fills as soft magnetic materials such as pure iron between permanent magnetic material.The periodic permanent magnet beam forming system is in light weight, and cost is low, does not need extra energy source device, is the first-selected beam forming system of travelling wave tube therefore.But the magnetic field that the periodic permanent magnet beam forming system can provide is very limited, and far away more from the surface of the permanent magnet of periodic permanent magnet beam forming system, magnetic field is more little.In the travelling wave tube, beam forming system is placed on the metallic shield enclosure, and when the cross sectional dimensions of slow wave line was big, beam forming system will be farther from the center of electron beam motion, the magnetic field of electron beam region will be a little less than.
The tradition travelling wave tube utilizes basic mode work usually.In the space at the slow wave line place of metallic shield shell seal, at synchronization, the distribution on the slow wave line cross section of electromagnetic electric field or magnetic-field component is by the common decision of electromagnetic frequency, slow wave line and metal boundary condition.Can electromagnetic wave be divided into different patterns according to the difference of this distribution, the simplest pattern of field distribution is called basic mode, and all the other patterns are referred to as higher modes.Generally speaking, the pattern difference, wave frequency also is different, the frequency of basic mode is minimum.Because basic mode and the corresponding to electric field component of electron beam velocity attitude are stronger, and be also strong to the effect of electron beam, the interaction efficiency height, so travelling wave tube utilizes basic mode work usually.
For slow wave line, have only the electromagnetic wave in the special frequency channel to transmit therein, this special frequency channel is called as the passband of slow wave line.The electromagnetic wave that is in lower limb on the slow wave line passband is exaggerated easily, and electromagnetic work forms and disturbs to basic mode, causes the travelling wave tube job insecurity, and this phenomenon is called as the band edge vibration.Band edge vibration is in that to use coupling cavity, folded waveguide etc. to have in the travelling wave tube of slow wave line in shape such as open chamber the most serious.
The reasons such as noise that produce owing to electron beam are in travelling wave tube, although amplitude might be very faint, always the higher modes electromagnetic wave exists.If the electromagnetic phase velocity of higher modes equates substantially that with the speed of electron beam this higher modes electromagnetic wave will be exaggerated, thereby disturb the electromagnetic work of basic mode, make the travelling wave tube job insecurity.In the travelling wave tube that uses helix as slow wave line, it is very low on certain frequency that this situation shows as power output, often is called as " power hole " phenomenon.
When the vibration of " power hole " or band edge occurring, the electromagnetic wave of competing with basic mode electromagnetism phase of wave all is the higher modes electromagnetic wave, and electromagnetic frequency of higher modes and basic mode are inequality.Therefore, if the metallic shield shell is replaced with a structure with filter function, it is extraneous that the higher modes electromagnetic wave can be arrived by this structural transmission, thereby filtered device filters, the basic mode electromagnetic wave is then unaffected, just can solve " power hole " and band edge oscillation problem.Because the effect of metallic shield shell provides vacuum environment, therefore require this filter structure that vacuum environment should be able to be provided.
Photonic crystal is the brand-new artificial material of a class that grows up at optical field in the recent period.As Fig. 3, Fig. 4, shown in Figure 5, photonic crystal is by two or more materials (two or more media, perhaps a kind of medium and a kind of metal, or multiple medium and multiple metal) alternately occur by certain way in the space and arrangement forms, generally, spatially being periodic distribution by a kind of material becomes prospect material 11, and another kind of material then background material 12 occurs becoming as the background of this material.Direction vector by prospect material 11 periodic arrangement can be divided into one dimension, two and three dimensions photonic crystal.The characteristics of photonic crystal are to have photon band gap, and promptly photonic crystal has filter action, and the electromagnetic wave in the special frequency channel can not see through photonic crystal and propagate, and this special frequency channel is called as photon band gap.
Summary of the invention
The objective of the invention is when making travelling wave tube can realize the pack electron beam function that can filter the higher modes electromagnetic wave, a kind of slow wave line that is used for travelling wave tube is provided.
To achieve these goals, the technical solution adopted in the present invention is: a kind of slow wave line that is used for travelling wave tube, follow the electron beam channel axially-aligned of wave duct by many groups photonic crystal elements, the inside of described photonic crystal elements is hollow structure, the hollow structure of many group photonic crystal elements is formed the electron beam channel of travelling wave tube, the prospect material of described photonic crystal elements radially is two-dimensional and periodic and arranges, described background material is filled the gap of full prospect material, be fixed together by the metal partion (metp) that is periodic arrangement in the axial direction between the photonic crystal elements and by its isolation, the prospect material of described photonic crystal elements uses the alloy permanent magnetic material, background material adopts ferrite permanent-magnet materials, and metal partion (metp) adopts soft magnetic material.
To achieve these goals, another program that also provides of the present invention: a kind of slow wave line that is used for travelling wave tube, follow the electron beam channel axially-aligned of wave duct by many groups photonic crystal elements, described photonic crystal elements symmetry is divided into two row up and down, dwell set between the two row photonic crystal elements becomes the electron beam channel of travelling wave tube, the prospect material of described photonic crystal elements radially is two-dimensional and periodic and arranges, described background material is filled the gap of full prospect material, be fixed together by metal partion (metp) between the photonic crystal elements and by its isolation, the prospect material of described photonic crystal elements uses the alloy permanent magnetic material, background material adopts ferrite permanent-magnet materials, and metal partion (metp) adopts soft magnetic material.
The invention has the beneficial effects as follows: in a structure, realized the pack electron beam simultaneously, provide slow electromagnetic wave and filtering higher modes electromagnetic three functions.Its principle is: at first, in fact the hybrid structures of periodic soft magnetic material and permanent magnetic material is exactly a kind of permanent-magnet structure that changes the cycle, can provide and the conventional suitable magnetic field of periodic permanent magnet beam forming system, and electron beam channel is close to this structure inner surface, the distance of the two is very near, so this structure ability that magnetic field is provided is identical with former periodic permanent magnet beam forming system.Secondly, when the internal communication of electromagnetic wave in this structure, because this structure is a kind of periodic structure, electromagnetic phase velocity can equate with electron beam speed substantially less than the light velocity, so this structure does not need extra circuit structure that the electromagnetism slow wave is provided.At last, such one-period array is again a kind of special photonic crystal, has photon band gap and filter function, as long as each structural parameters are obtained rationally, and just can filtering higher modes electromagnetic wave; And, when the higher modes electromagnetic wave enters when wherein transmitting, can be subjected to the strong magnetic loss of this structure, further reached the electromagnetic purpose of elimination higher modes, and the basic mode electromagnetic wave is within the photon band gap, enter after this structure, by this structure institute total reflection, its magnetic loss that is subjected to is limited soon.
Description of drawings
Fig. 1 is the structural principle schematic diagram of the travelling wave tube of prior art.
Fig. 2 is the one-dimentional structure schematic diagram of the photonic crystal of prior art.
Fig. 3 is the two-dimensional structure schematic diagram of the photonic crystal of prior art.
Fig. 4 is the three-dimensional structure schematic diagram of the photonic crystal of prior art.
Fig. 5 is the perspective view of the embodiment of the invention one.
Fig. 6 is the embodiment of the invention one cutaway view vertically.
Fig. 7 is the embodiment of the invention one cutaway view radially.
Fig. 8 is the structural principle schematic diagram of the embodiment of the invention one applied travelling wave tube.
Fig. 9 is the perspective view of the embodiment of the invention two.
Figure 10 is the embodiment of the invention two cutaway view vertically.
Figure 11 is the embodiment of the invention two cutaway view radially.
Description of reference numerals: electron gun 1, slow wave line 2, beam forming system 3, collector 4, metallic shield shell 5, input waveguide 6, output waveguide 7, electron beam channel 8, electromagnetic wave 9, electron beam 10, prospect material 11, background material 12, metal partion (metp) 13, photonic crystal elements 14.
Embodiment
Below in conjunction with the drawings and specific embodiments the present invention is described in detail.
Embodiment 1: as Fig. 5, Fig. 6 and shown in Figure 7.A kind of slow wave line that is used for travelling wave tube, follow electron beam channel 8 axially-aligned of wave duct by many groups photonic crystal elements 14, the inside of described photonic crystal elements 14 is hollow structure, the hollow structure of many group photonic crystal elements 14 is formed the electron beam channel 8 of travelling wave tube, the prospect material 11 of described photonic crystal elements 14 radially is two-dimensional and periodic and arranges, described background material 12 is filled the gap of full prospect material 11, is fixed together by the metal partion (metp) 13 of periodic arrangement in the axial direction between the photonic crystal elements 14 and by its isolation.The prospect material 11 of described photonic crystal elements 14 uses the alloy permanent magnetic material, as SmCo (SmCo), neodymium iron boron (Nd2Fe14B) or aluminium nickel cobalt materials such as (AlNiCo); Background material 12 adopts ferrite permanent-magnet materials; Metal partion (metp) 13 adopts soft magnetic material, as pure iron or ferroalloy.In the present embodiment, the mode by welding between the photonic crystal elements is fixedly connected between the metal partion (metp) 13.In the present embodiment, the cross section of photonic crystal elements 14 is annular, and middle through hole has formed circular electron beam channel 8.
As shown in Figure 8, when present embodiment is applied in the travelling wave tube, when the internal communication of electromagnetic wave 9 in this structure, because this structure is a kind of periodic structure, the phase velocity of electromagnetic wave 9 can equate with electron beam 10 speed substantially less than the light velocity, so this structure does not need extra circuit structure that the electromagnetism slow wave is provided.At last, such one-period array is again a kind of special photonic crystal, has photon band gap and filter function, as long as each structural parameters are obtained rationally, and just can filtering higher modes electromagnetic wave; And, when the higher modes electromagnetic wave enters when wherein transmitting, can be subjected to the strong magnetic loss of this structure, further reached the electromagnetic purpose of elimination higher modes, and the basic mode electromagnetic wave is within the photon band gap, enter after this structure, by this structure institute total reflection, its magnetic loss that is subjected to is limited soon.
Embodiment 2: as Fig. 9, Figure 10 and shown in Figure 11, a kind of slow wave line that is used for travelling wave tube, follow electron beam channel 8 axially-aligned of wave duct by many groups photonic crystal elements 14, described photonic crystal elements 14 symmetries are divided into two row up and down, dwell set between the two row photonic crystal elements 14 becomes the electron beam channel 8 of travelling wave tube, the prospect material 11 of described photonic crystal elements 14 radially is two-dimensional and periodic and arranges, described background material 12 is filled the gap of full prospect material 11, is fixed together by metal partion (metp) 13 between the photonic crystal elements 14 and by its isolation.The prospect material 11 of described photonic crystal elements 14 uses the alloy permanent magnetic material, as SmCo (SmCo), neodymium iron boron (Nd2Fe14B) or aluminium nickel cobalt materials such as (AlNiCo); Background material 12 adopts ferrite permanent-magnet materials; Metal partion (metp) 13 adopts soft magnetic material, as pure iron or ferroalloy.In the present embodiment, the mode by welding between the photonic crystal elements is fixedly connected between the metal partion (metp) 13.In the present embodiment, the cross section of photonic crystal elements 14 is rectangular, and the gap between the two row photonic crystal elements has formed the electron beam channel 8 of rectangle up and down.
By to the foregoing description structure optimization design, the basic mode electromagnetic wave is within the photon band gap, and the higher modes electromagnetic wave is in outside the photon band gap.Because be subjected to the total reflection of this structure, the electromagnetic field energy of basic mode mainly concentrates near the electron beam channel, the higher modes electromagnetic wave then can enter this structure and transmit to extraneous space, is subjected to strong magnetic loss simultaneously.Like this, just avoided of the interference of higher modes electromagnetic wave to the work of basic mode electromagnetic wave.
Those of ordinary skill in the art will appreciate that embodiment described here is in order to help reader understanding's principle of the present invention, should to be understood that protection scope of the present invention is not limited to such special statement and embodiment.Those of ordinary skill in the art can make various other various concrete distortion and combinations that do not break away from essence of the present invention according to these technology enlightenments disclosed by the invention, and these distortion and combination are still in protection scope of the present invention.
Claims (2)
1. slow wave line that is used for travelling wave tube, follow the electron beam channel axially-aligned of wave duct by many groups photonic crystal elements, it is characterized in that, the inside of described photonic crystal elements is hollow structure, the hollow structure of many group photonic crystal elements is formed the electron beam channel of travelling wave tube, the prospect material of described photonic crystal elements radially is two-dimensional and periodic and arranges, described background material is filled the gap of full prospect material, be fixed together by the metal partion (metp) that is periodic arrangement in the axial direction between the photonic crystal elements and by its isolation, the prospect material of described photonic crystal elements uses the alloy permanent magnetic material, background material adopts ferrite permanent-magnet materials, and metal partion (metp) adopts soft magnetic material.
2. slow wave line that is used for travelling wave tube, follow the electron beam channel axially-aligned of wave duct by many groups photonic crystal elements, it is characterized in that, described photonic crystal elements symmetry is divided into two row up and down, dwell set between the two row photonic crystal elements becomes the electron beam channel of travelling wave tube, the prospect material of described photonic crystal elements radially is two-dimensional and periodic and arranges, described background material is filled the gap of full prospect material, be fixed together by metal partion (metp) between the photonic crystal elements and by its isolation, the prospect material of described photonic crystal elements uses the alloy permanent magnetic material, background material adopts ferrite permanent-magnet materials, and metal partion (metp) adopts soft magnetic material.
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| CN2010101183995A CN101770919B (en) | 2010-03-05 | 2010-03-05 | Slow wave line for travelling wave tube |
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| CN2010101183995A CN101770919B (en) | 2010-03-05 | 2010-03-05 | Slow wave line for travelling wave tube |
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| CN101770919B CN101770919B (en) | 2012-06-20 |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101840834A (en) * | 2010-03-05 | 2010-09-22 | 电子科技大学 | Trapezoidal slow wave lines of coupling slot for traveling wave tube |
| CN103137398B (en) * | 2013-01-22 | 2015-10-14 | 中国电子科技集团公司第十二研究所 | A kind of multi-frequency shunt Terahertz traveling-wave tube frequency multiplier |
| CN108335958A (en) * | 2018-02-07 | 2018-07-27 | 电子科技大学 | A kind of double note slow-wave structures of winding waveguide of photonic crystal load |
| CN111640636A (en) * | 2020-06-09 | 2020-09-08 | 电子科技大学 | Traveling wave tube slow wave circuit working at positive and second spatial harmonics |
| CN114005720A (en) * | 2021-11-09 | 2022-02-01 | 北京航空航天大学 | Terahertz traveling wave tube slow wave focusing integrated structure and manufacturing method thereof |
| WO2023273906A1 (en) * | 2021-06-30 | 2023-01-05 | 华为技术有限公司 | Slow wave circuit, electromagnetic wave processing method, and related device |
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| WO2005017939A2 (en) * | 2003-06-30 | 2005-02-24 | Massachusetts Institute Of Technology | Ribbon-beam travelling wave amplifier with a single-sided slow-wave structure |
| CN100479260C (en) * | 2007-02-07 | 2009-04-15 | 东南大学 | Slow wave structure based on electromagnetic band gap structure |
| CN201663142U (en) * | 2010-03-05 | 2010-12-01 | 电子科技大学 | Slow wave line for traveling-wave tube |
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2010
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Patent Citations (4)
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| US4072877A (en) * | 1976-07-30 | 1978-02-07 | English Electric Valve Co., Ltd. | Travelling wave tubes |
| WO2005017939A2 (en) * | 2003-06-30 | 2005-02-24 | Massachusetts Institute Of Technology | Ribbon-beam travelling wave amplifier with a single-sided slow-wave structure |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101840834A (en) * | 2010-03-05 | 2010-09-22 | 电子科技大学 | Trapezoidal slow wave lines of coupling slot for traveling wave tube |
| CN103137398B (en) * | 2013-01-22 | 2015-10-14 | 中国电子科技集团公司第十二研究所 | A kind of multi-frequency shunt Terahertz traveling-wave tube frequency multiplier |
| CN108335958A (en) * | 2018-02-07 | 2018-07-27 | 电子科技大学 | A kind of double note slow-wave structures of winding waveguide of photonic crystal load |
| CN111640636A (en) * | 2020-06-09 | 2020-09-08 | 电子科技大学 | Traveling wave tube slow wave circuit working at positive and second spatial harmonics |
| CN111640636B (en) * | 2020-06-09 | 2021-03-30 | 电子科技大学 | Traveling wave tube slow wave circuit working at positive and second spatial harmonics |
| WO2023273906A1 (en) * | 2021-06-30 | 2023-01-05 | 华为技术有限公司 | Slow wave circuit, electromagnetic wave processing method, and related device |
| CN114005720A (en) * | 2021-11-09 | 2022-02-01 | 北京航空航天大学 | Terahertz traveling wave tube slow wave focusing integrated structure and manufacturing method thereof |
| CN114005720B (en) * | 2021-11-09 | 2022-10-14 | 北京航空航天大学 | Terahertz traveling wave tube slow wave focusing integrated structure and manufacturing method thereof |
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