RU2631923C1 - Superhigh-frequency cyclotron protective device - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: superhigh-frequency cyclotron protective device comprises a tape cathode, a focusing electrode installed in front of the cathode and made in the form of a rectangular plate with edges bent at right angles to the cathode, an anode, a resonator system with input and output volume resonators having unidirectional coupling with each other through the electron beam and interacting with a fast cyclotron wave of the electron beam. Each resonator is connected and matched to UHF-lines by a signal transmission path, an electron collector, a magnetic system on permanent magnets longitudinally magnetized along the propagation direction of the electron beam, mounted on opposite inner walls of a rectangular magnetic circuit and provided with pole pieces. The magnetic system contains four additional magnets magnetized in a direction perpendicular to the propagation direction of the electron beam. Each magnet is located between the side walls of the pole piece and the magnetic circuit and adjoins with a magnetic pole, the cognominal pole of the longitudinally magnetized permanent magnet. The electron collector is made in the form of two thin mutually parallel plates on a wire holder mounted in the cylindrical cavity of the pole piece which axis is oriented perpendicular to the direction of propagation of the tape electron beam along its width.

EFFECT: increasing the frequency of the CPD and expanding the scope of the CPD in the radar receivers of the 8-millimeter wavelength range to protect them from the effects of high-level input power.

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Description

The invention relates to the field of high-frequency radio electronics, and in particular, to devices for protection against the effects of input power of a high level in microwave radio receivers, in particular in radar receivers of an 8-mm wavelength range.

In modern radar stations (radar), stringent requirements are imposed on the input stages of the receiver. Along with a small noise figure in the working frequency band, they must be reliably protected from high-level microwave power with an extremely short recovery time after the microwave pulse ends.

In the totality of these requirements, the most promising are cyclotron protective devices (CZU) operating on a fast cyclotron wave (BCV) of the electron beam. They have a number of technical advantages over solid-state and gas-discharge protective devices: uniquely small (on the order of nanoseconds) response and restoration of the operating mode after the end of a high power pulse, a high level of permissible input power (up to several tens of kilowatts per pulse), low signal loss, low level noise, linearity of amplitude and phase characteristics.

, где η=e/m - отношение заряда электрона к его массе, В - индукция продольного магнитного поля. Взаимодействие СВЧ-полей резонаторов с БЦВ электронного потока происходит на частоте входного сигнала

, совпадающей с циклотронной частотой

и собственной частотой резонаторов в центре рабочей полосы частот

.The physical principle of the central locking system is based on the interaction of the microwave field of the resonators with an extended capacitive gap with the field of the central electron beam flow associated with the rotation of electrons in a longitudinal magnetic field with a cyclotron frequency

, where η = e / m is the ratio of the electron charge to its mass, B is the induction of the longitudinal magnetic field. The interaction of the microwave fields of the resonators with the central electron beam of the electron beam occurs at the frequency of the input signal

coinciding with the cyclotron frequency

and the natural frequency of the resonators in the center of the working frequency band

.

и соответственно индукцией поля В=0.35 Тл, которые широко применяются в приемных устройствах РЛС см-диапазона и обеспечивают их эффективную защиту от воздействия входной мощности большого уровня в условиях радиопротиводействия.At present, CMUs of the sm-range of wavelengths at a frequency of up to

and, accordingly, the field induction B = 0.35 T, which is widely used in cm-band radar receivers and provides their effective protection against the effects of a large input power level under radio interference conditions.

с уровнем индукции поля B=1.3 Тл [1]. Однако в настоящее время ЦЗУ для этого частотного диапазона не разработаны.An urgent task is to create a central memory for the protection of radar receivers of the 8 mm wavelength range at a frequency

with the field induction level B = 1.3 T [1]. However, at present, DLCs for this frequency range have not been developed.

Closest to the proposed invention (prototype) is a central bank of a 3-centimeter wavelength range [2, 3].

на частоте входного сигнала

в центре рабочей полосы частот

. Резонаторы взаимодействуют с БЦВ электронного потока и имеют однонаправленную связь друг с другом через электронный поток, при этом каждый резонатор соединен и согласован с внешними СВЧ-линиями трактом передачи сигнала. Взаимодействие СВЧ-полей резонаторов с БЦВ электронного потока происходит на частоте входного сигнала

в центре рабочей полосы частот, равной циклотронной частоте

в продольном магнитном поле с индукцией В=0.35 Тл. Магнитное поле создается с помощью магнитной системы на постоянных магнитах, намагниченных в продольном направлении распространения электронного потока, установленных на противоположных внутренних стенках прямоугольного магнитопровода и снабженных полюсными наконечниками. Коллектор электронов представляет собой полый цилиндр с закрытым дном и входным прямоугольным отверстием для пропускания ленточного электронного потока, установленный внутри полости полюсного наконечника для обеспечения его магнитной экранировки от магнитного поля в междуполюсном зазоре.The prototype device [2, 3] contains a tape cathode, a focusing electrode mounted in front of the cathode and made in the form of a rectangular plate with edges bent at right angles to the cathode, an anode, a resonator system with input and output volume resonators with natural frequency, equal cyclotron frequency

at input frequency

in the center of the working frequency band

. The resonators interact with the central electronic circuit of the electron beam and have unidirectional communication with each other through the electron beam, with each resonator connected and matched to external microwave lines by a signal transmission path. The interaction of the microwave fields of the resonators with the central electron beam of the electron beam occurs at the frequency of the input signal

in the center of the working frequency band equal to the cyclotron frequency

in a longitudinal magnetic field with induction B = 0.35 T. The magnetic field is created using a permanent magnet magnet system, magnetized in the longitudinal direction of electron flow propagation, mounted on opposite inner walls of a rectangular magnetic circuit and equipped with pole tips. The electron collector is a hollow cylinder with a closed bottom and a rectangular inlet for transmitting a tape electron stream, mounted inside the cavity of the pole piece to ensure its magnetic shielding from the magnetic field in the interpolar gap.

, B=1.3 Тл) необходимы изменения конструкции его основных узлов, включая магнитную, резонаторную и коллекторную системы.The disadvantage of the ZZU prototype is that it works in a limited area of the operating frequencies of the cm-wavelength range. For the operation of the central memory in a different frequency range and, namely, in radar receivers of the 8 mm wavelength range (

, B = 1.3 T) necessary changes in the design of its main components, including magnetic, resonator and collector systems.

The technical result of the invention is to increase the frequency of the central bank and expand the scope of the central bank in radar receivers of the 8 mm wavelength range to protect them from the effects of input power of a large level.

The technical result is achieved by the fact that the proposed microwave cyclotron protective device comprises a tape cathode, a focusing electrode mounted in front of the cathode and made in the form of a rectangular plate with edges bent at right angles to the cathode, an anode, a resonator system with input and output volume resonators, having unidirectional communication with each other through the electron beam and interacting with the fast cyclotron wave of the electron beam, with each the resonator is connected and matched with external microwave lines by a signal transmission path, an electron collector, a permanent magnet magnet system, longitudinally magnetized along the propagation direction of the electron beam, mounted on opposite inner walls of a rectangular magnetic circuit and equipped with pole tips. The magnetic system contains four additional magnets magnetized in a direction perpendicular to the direction of propagation of the electron beam, each magnet located between the side walls of the pole piece and the magnetic circuit and adjacent to them by a magnetic pole of the same name as the longitudinally magnetized permanent magnet. The electron collector is made in the form of two thin mutually parallel plates on a wire holder mounted in a cylindrical cavity of the pole tip, the axis of which is oriented perpendicular to the direction of propagation of the tape electron stream along its width.

The use in the magnetic system of four additional magnets magnetized in the direction perpendicular to the direction of propagation of the electron flux located between the side walls of the pole piece and the magnetic circuit adjacent to them by a magnetic pole of the same name to the pole of a longitudinally magnetized permanent magnet, allows the formation of a uniform longitudinal magnetic field, necessary to ensure the work of the proposed DLC at a higher frequency in the 8 mm wavelength range.

The execution of the collector assembly in the form of two thin mutually parallel plates mounted on a wire holder mounted inside a cylindrical cavity in the collector pole piece, the axis of which is oriented perpendicular to the direction of propagation of the electron beam along its width, provides effective magnetic shielding of the collector from the magnetic field and thereby improves noise Parameters of the proposed 8-millimeter wavelength range.

The invention is illustrated by drawings.

In FIG. 1 shows a block diagram of the proposed 8-millimeter wavelength range, where:

- tape cathode 1;

- focusing electrode 2;

- anode 3;

- input resonator 4;

- output resonator 5;

- electronic stream 6;

- signal transmission path 7;

- electron collector 8;

- a permanent magnet with a longitudinal magnetization of 9;

- rectangular magnetic circuit 10;

- pole tip 11;

- an additional magnet with transverse magnetization 12.

In FIG. 2a shows the magnetic system of the proposed DLC of the 8 mm wavelength range (volume fragment 1/4 of the part), where:

- a permanent magnet with a longitudinal magnetization of 9;

- rectangular magnetic circuit 10;

- pole tip 11;

- an additional magnet with transverse magnetization 12.

In FIG. 2 (b) shows a graph of the distribution function of the longitudinal component of the field induction along the axis of the magnetic system (X = Y = 0), where

- Bz - magnetic field induction.

In FIG. Figure 3 shows the collector of the proposed central 8-millimeter wavelength range (volume fragment of a 1/2 part) (a) and its projection onto the plane (Y = 0) (b), where:

- electron collector 8;

- pole tip 11;

- collector plates 13;

- wire holder collector 14;

- cylindrical cavity 15.

In FIG. 4. shows the distribution of current density over the cross section of the tape electron stream in the proposed DLC 8-mm wavelength range.

The device contains sequentially located one after the other a focusing electrode 2, a tape cathode 1, anode 3, an input resonator 4 and an output resonator 5 with signal transmission paths 7 having unidirectional communication with each other through a tape electronic stream 6, collector 8. An armored type magnetic system contains a rectangular magnetic circuit 10, two permanent magnets 9 mounted on two opposite inner walls of the magnetic circuit 10, magnetized in the same direction of propagation of the electron beam 6 and equipped with pole pieces 11. Between the side walls of the pole pieces 11 and the inner walls of the magnetic circuit 10 there are four additional magnets 12, each of which is magnetized in a direction perpendicular to the direction of propagation of the electron flux 6, and oriented with its magnetic poles in such a way that it is adjacent to the walls of the pole pieces 11 and the inner walls of the magnetic circuit 10 with magnetic poles, the same poles of the longitudinally magnetized magnets 9. The collector 8 is installed inside the indricheskoy cavity 15 of the pole piece 11. The collector 8 consists of two parallel collector plates 13 mounted on the collector wire holder 15.

Microwave cyclotron protective device of the 8 mm wavelength range works as follows.

в 8-миллиметровом диапазоне длин волн. После взаимодействия с полями резонаторов 4, 5 электронный поток 6 поступает в коллектор 8. Благодаря электрической изоляции коллектора 8 и, следовательно, возможности подачи на него потенциала Uколл, многократно превышающего потенциал Uo резонаторов 4, 5 (Uколл»Uo), а также благодаря резкому спаду индукции поля в области коллектора 8 вследствие его магнитной экранировки устраняется возможность попадания в емкостной зазор выходного резонатора 5 вторично-эмиссионных электронов из облучаемой поверхности коллектора 8 (пластин 13 и держателя 14), которые вызывают шумовые «всплески» в рабочей полосе частот и ухудшают шумовые характеристики ЦЗУ.In the transmission mode, the input signal comes from the signal transmission path 7 to the input resonator 4. Under its influence, an electron beam CCV is excited in the electron stream 6, which transmits the signal energy to the output resonator 5 and further along the signal transmission path 7 to the external microwave line. In the gap between the pole pieces 11, the direction of the magnetic fluxes of the additional magnets 12 with transverse magnetization coincides with the magnetic flux of magnets 9 with longitudinal magnetization, which makes it possible to increase the field induction to the level B = 1.3 T for the effective interaction of the fields of the resonators 4, 5 with the CCF of the electron beam by center frequency

in the 8 mm wavelength range. After interacting with the fields of the resonators 4, 5, the electron stream 6 enters the collector 8. Due to the electrical isolation of the collector 8 and, therefore, the possibility of supplying to it a potential Ucol, many times higher than the potential Uo of the resonators 4, 5 (Ucol ”Uo), and also due to the sharp the decrease in field induction in the region of the collector 8 due to its magnetic shielding eliminates the possibility of secondary emission electrons entering the capacitive gap of the output resonator 5 from the irradiated surface of the collector 8 (plates 13 and holder 14), cat Others cause noise "bursts" in the working frequency band and degrade the noise characteristics of the central memory.

The technical feasibility of the proposed 8-millimeter waveguide 8-millimeter wavelength range is confirmed by computer simulation.

The simulation was performed in the XYZ Cartesian coordinate system based on the use of 3D models of magnetic and electron-optical systems, taking into account the action of the intrinsic space charge of the tape electron beam.

On the volume fragment of 1/4 part of the magnetic system of the proposed RAM 8-mm wavelength range shown in FIG. 2a, parts of the magnetic circuit 10, permanent magnets 9 with longitudinal magnetization, pole pieces 11, permanent magnets 12 with transverse magnetization are shown.

The flat side and end walls of the magnetic circuit 10 have dimensions in the XYZ coordinates equal to 45 × 5 × 62 mm ³ and 43 × 30 × 2 mm ³ , respectively. Magnets 9 with longitudinal magnetization have the same dimensions 40 × 10 × 15 mm ³ and are installed in the plane of longitudinal symmetry Y = 0 of the magnetic circuit 10. Magnet 9 is adjacent to one plane to the inner end wall of the magnetic circuit 10, and the opposite plane to the pole piece 11. Pole tip 11 has the shape of a pyramid with flat side walls facing the side of the inner inner walls of the magnetic circuit 10. From the side of the magnetic gap, the pole pieces 11 have a square shape with a cross section of 10 × 10 mm ² . The pole pieces 11 face each other with their peaks and form an interpolar gap of length 0 <Z <Zk, where Zk = 9.3 mm. In this gap are located: cathode 1, focusing electrode 2, anode 3, input 4 and output 5 resonators. Between the side wall of the magnetic circuit 10 and the flat side wall of the pole piece 11, a magnet 12 with transverse magnetization with a size of 40 × 10 × 25 mm ^{3 is} installed. All magnets 9 and 12 are made of samarium-cobalt alloy, the magnetic core 10 and pole pieces 11 are made of Armco steel.

The graph of the distribution function of the longitudinal component of the field induction along the axis of the magnetic system (X = Y = 0) (Fig. 2b) shows that a magnetic field is formed in this magnetic system with induction at the level of Bz = 1.3 T, which is close to uniform in the region 0 <Z <9.0 and sharply falling in the reservoir area 9.0 <Z.

On the volume fragment of 1/4 of the proposed central 8-millimeter wavelength range, the design of the collector assembly 8 is shown (Fig. 3a). In FIG. 3b shows its projection on the plane Y = 0. The collector 8 consists of two thin mutually parallel plates 13 on a wire holder 14 mounted on the axis of the cylindrical cavity 15 inside the pole piece 11. The axis of the cylindrical cavity 15 with the holder 14 is directed along the Y coordinate, i.e. along the width of the tape electron stream 6 perpendicular to the direction of its propagation. The plates 13 with the holder 14 are electrically isolated from the collector pole piece 11.

The distribution of current density over the cross section of the tape electron stream in the proposed DLC of the 8 mm wavelength range is shown in FIG. 4. The calculation was carried out at different distances from the plane of the pole tip 11, including the emitter plane (Z = 3.3 mm), input (Z = 4.9 mm) and output (Z = 6.1 mm) plane of the capacitive gap of the input cavity 4, input (Z = 7.4 mm) and the output (Z = 8.6 mm) plane of the capacitive gap of the output resonator 5, as well as the input plane (Z = 9.3 mm) of the pole piece 11 with a cylindrical collector cavity 15. The transverse dimensions (along the X and Y coordinates) of the emitting surface of the tape cathode 1 equal to 0.022 × 0.75 mm ² , the capacitive gaps of the input 4 and output 5 resonators - 0.05 × 0.60 mm ² . The calculation was performed at the following given potentials: focusing electrode 2 (Uph = -30V), anode 3 (Ua = + 13B) of the input and output resonators 4, 5 (Uo = + 16B), collector 8 (Ucoll = + 250V). The calculated value of the current (micropervance) of the tape electron stream is 186 μA (2.9 μA / V ^3/2 ).

The presented simulation results prove the possibility of high-quality rigid focusing of an ultrathin ribbon electron stream with transverse dimensions close to the dimensions of the emitting surface of the cathode without distorting its edges, which is necessary for realizing the effective interaction of the resonator fields with the central electron beam in the proposed 8-millimeter wavelength range.

Thus, the frequency of the proposed microwave cyclotron protective device is increased compared to the prototype 4 times, which is necessary to protect the radar receivers of the 8 mm wavelength range from the effects of the input power of a large level. The creation of the invention will allow to realize the well-known advantages of the central memory in the radar of the 8-mm wavelength range, to increase the stability of their work in the conditions of radio interference.

Information sources

1. Yu.A. Budzinsky, S.V. Bykovsky, I.I. Golenitsky, V.G. Viburnum. Formation, development and prospects of microwave devices based on cyclotron resonance of an electron beam. // Electronic equipment. Series 1. Microwave technology. Part 1. Vol. 3 (518). 2013, pp. 136-142.

2. Patent of the Russian Federation No. 2530746, IPC Н02Н 7/00. Published: October 10, 2014. Bulletin No. 28.

3. I.I. Golenitsky, N.G. Dukhina, E.I. Kanevsky. Comprehensive calculation of three-dimensional electron-optical and magnetic focusing systems of microwave electron-beam composites. Section 4. Tape electronic flow in the central memory. // Electronic equipment. Ser. 1. Microwave technology. Vol. 2 (482). 2003, S. 60-65.

Claims (1)

Microwave cyclotron protective device containing a tape cathode, a focusing electrode mounted in front of the cathode and made in the form of a rectangular plate with edges bent at right angles to the cathode, an anode, a resonator system with input and output volume resonators having unidirectional communication with each other through the electron beam and interacting with the fast cyclotron wave of the electron beam, with each resonator connected and matched to external microwave lines a signal transmission path, an electron collector, a permanent magnet magnet system longitudinally magnetized along the electron flux propagation direction, mounted on opposite inner walls of a rectangular magnetic circuit and provided with pole pieces, characterized in that the magnetic system contains four additional magnets magnetized in a direction perpendicular to electron flow propagation, with each magnet located between the side walls of the pole the tip and the magnetic circuit and adjacent to them by a magnetic pole of the same name as the pole of a longitudinally magnetized permanent magnet, the electron collector is made in the form of two thin mutually parallel plates on a wire holder mounted in a cylindrical cavity of the pole piece, the axis of which is oriented perpendicular to the direction of propagation of the tape electron beam along its width .

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