RU34279U1 - KLYSTRON - Google Patents

Description

The utility model relates to the field of microwave microwave devices, in particular to medium-power klystrons used as terminal amplifiers in transmitters of radar stations, communication systems, and other radio engineering installations operating in continuous and quasi-pulse modes in the short-wavelength part of the centimeter and long-wavelength parts of the millimeter range .

Known klystron medium power (RF patent No. 2075131, class IPC H01J25 / 10, published 03/10/1997), containing a multipath electron gun, electron collector, input and output of energy, input, output and intermediate single-gap ring resonators. The resonators are made in the form of segments of a U-shaped waveguide folded into a ring. The dimensions of the resonators provide for excitation of a standing wave of the Nuo type in the operating frequency range. In the resonator waveguides, the space between the opposite walls in the form of a rectangular protrusion and a plane forms an annular microwave gap along which the passage channels are periodically located so that their axes are parallel to the resonator axis. To prevent excitation of resonators on other types of waves, at least one of the resonators has radial slots located diametrically opposite in the plane of the input / output energy. Absorption elements are installed in the slots.

However, this design of the klystron is not suitable for use in the short-wavelength part of the centimeter and long-wave part of the millimeter range, because the resonators used in this wavelength range are very small. Due to this, they have a small Q factor Q and a small total area of the openings of the passage channels, limiting the total current of the multipath electron beam in the range of 0.4-0.6 A. Therefore, it is impossible to realize a large output microwave power (above one kilowatt) and a large gain (above 35 dB ) when operating in a non-reprogrammed and quasi-pulsed mode with a low (not higher than five kilovolts) accelerating voltage at the resonators.

Also known is a medium power klystron (RF patent No. 2125319, class IPC H01J25 / 10, published January 20, 1999) containing a multi-beam electron gun, electron collector, energy input and output, input, output, and intermediate two-gap linear resonators made in in the form of segments of a coaxial waveguide shorted at the ends. The dimensions of the resonators provide in the range of operating frequencies

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   NH01J25 / 10

KLYSTRON

excitation of a standing wave of the Noi type. The space between the inner conductor and the waveguide wall forms two successive microwave gaps in the direction of electron motion. The span channels are located linearly along the waveguide axis, in two rows so that their axes are perpendicular to the axis of the waveguide, the distance between adjacent span channels is the same, and the length of each row of channels does not exceed 0.25 L, where A is the wavelength in the waveguide.

However, this design of the klystron is also not suitable for use in the shortwave of the centimeter and longwave of the millimeter range for the same reasons as the previous design of the klystron.

Closest to the claimed one is a klystron (US patent No. 3248597, class NKI 315-5.16, published April 26, 1966) containing several electron guns and the corresponding number of electron collectors, input and output of microwave energy, input, output and intermediate single-gap linear resonators made in the form of shorted waveguides at the ends. The resonator dimensions in the operating frequency range de-energize the excitation of a standing Nyup-type wave. Microwave gaps are located along the waveguides in the maximum region of the transverse component of the electric microwave field. The pole tips of the microwave gaps are made in the form of tube-shaped pins, forming, simultaneously, span channels and reflecting electrodynamic elements such as capacitive diaphragms. The axes of the passage channels in the microwave gaps are perpendicular to the axes of the resonator waveguides. Between the microwave gaps in the region of the maximum transverse component of the magnetic microwave field are rods forming reflective electrodynamic elements of the inductance diaphragm.

This design of the klystron is suitable for use in the shortwave of the centimeter and longwave of the millimeter range. In this case, the total current of the multipath electronic note can be significantly higher than 0.5 A due to the use of a large number of electronic lines. Therefore, this klystron allows you to realize large values of the output microwave power (above one kilowatt) in this wavelength range. However, with a low accelerating voltage at the resonators (several kilovolt units) and a low current density in electron beams (not higher than 10 A / cm), the electronic efficiency in it does not exceed 10-15%, and the gain is 10-15 dB, because the presence of only one microwave gap in the input, output, and intermediate resonators in the direction of electron motion does not provide the required efficiency of the interaction of electron beams with the microwave field. In addition, with a large output microwave power, the klystron can operate in the required wavelength range only in the pulsed mode, because when working in continuous and quasi-pulse modes, vacuum-tight dielectric windows are destroyed in known designs of microwave energy outputs.

The utility model is aimed at solving the problem of creating an average power klystron operating in continuous and quasi-pulse modes in the short-wavelength part of the centimeter and long-wavelength parts of the millimeter ranges, which has a high electronic efficiency, a large gain and a wide band of amplified frequencies.

To solve this problem, in a klystron containing several electron guns, an electron collector, input and output microwave energy, input, output and intermediate resonators in the form of rectangular waveguides, microwave gaps with span channels located in the region of the maxima of the transverse component of the microwave electric field so so that their axes are perpendicular to the axes of the resonator waveguides, reflecting the electrodynamic elements located between the microwave gaps in the region of the maximum transverse component of the magnetic microwave field, with According to the proposed utility model, microwave gaps are made in the form of multi-row structures of ribbon conductors located perpendicular to the axes of the resonator waveguides and the axes of the span channels, the microwave energy output is placed in the cavity additionally inserted into the klystron in the form of a rectangular waveguide, which is discretely connected to the output resonator waveguide in the regions maxima of the transverse component of the magnetic microwave field through the waveguide loops in the form of a rectangular waveguide containing vacuum-tight dielectric windows and resonant diaphragms, and the reflecting electrodynamic elements are made in the form of segments of a rectangular waveguide, in which a narrow wall is not less than half the narrow wall of the input, intermediate, and output resonators.

Multi-row structures of tape conductors located in the resonator waveguides in the region of the maxima of the transverse component of the microwave electric field form several microwave gaps in the direction of electron motion. This makes it possible to create several multi-gap spaces in the resonators in which the cascade interaction of electrons with the transverse component of the electric microwave field of the standing wave is realized. As calculations show, due to this, the intensity of the electron beam modulation in the input and intermediate cavities in velocity, which determines the value of the klystron gain, will be proportional to their Q factor and the number P of microwave gaps in the multi-gap space, and in the output resonator, the intensity of energy exchange between the microwave field and the resulting electron clusters,

i (wm) dividing the value of the electronic efficiency, will be proportional to Q and P in the multi-gap spaces of this resonator. In order for the intense and speed-modulated beams in the input and intermediate cavities to be provided at the wavelength λ of the input signal and the accelerating voltage V, the period length L between the ribbon conductors in multi-row structures should be given by the expression Z, “I (l / G / 505 | ( 1 + /) / P, corresponding to the fulfillment in the microwave gaps of the condition of spatial-phase synchronism between the microwave field and the forming electron clusters. In the output resonator, d.11 I ensure a high electronic efficiency, using length of the first period is determined by the length of the first period of multi-row structures, and the length of subsequent periods should be reduced according to the law, which ensures in the microwave gaps that the condition of spatial-phase synchronism is satisfied as the electron clusters decelerate. phase synchronization of microwave fields in the microwave gaps of multi-row structures.Placing the output of microwave energy in an additionally introduced cavity, the waveguide of which It is discretely coupled to the waveguide of the output resonator in the maximum regions of the transverse component of the magnetic microwave field through waveguides containing vacuum-tight dielectric windows, which makes it possible to reduce the fraction of the output microwave energy passing through each vacuum-tight dielectric window in proportion to the number of loops. The presence of resonant diaphragms in the waveguide loops allows us to provide the required value of the quality factor of the output resonator. For given values of modulation of electron beams in speed in the input and intermediate resonators and energy exchange in the output resonator, proportional to the Q factor of the resonators and the number of microwave gaps P in multi-row structures, the values of Q can be reduced by increasing P and thereby increasing the passband of the resonators and, therefore, increase the band of amplified frequencies. The utility model is illustrated by drawings, where in FIG. 1 is a front view of the klystron; FIG. 2 is a side view, in FIG. 3 is a plan view of FIG. 4 is a view of a multi-row structure, in FIG. 5 is a view of a tape conductor of a multi-row structure with span channels. The following notation is introduced on these figures: - electronic guns,

4-output resonator

5 - additionally introduced resonator,

6-waveguide loops,

7- input microwave energy

8 - output microwave energy

9 - multi-row structures in the input cavity,

10 - multi-row structures in an intermediate cavity,

11 - multi-row structures in the output cavity,

12-tape conductors of multi-row structures,

13-span channels for electron beams,

14 - reflecting electrodynamic elements,

15- vacuum-tight dielectric windows,

16- resonant diaphragms

17- electron collector,

18-pole magnetic focusing system tips

19- magnets,

20- reflecting electrodynamic elements having a transfer characteristic equivalent to the transfer characteristic of multi-row structures (11).

A klystron consists of several electron guns (1), an input linear resonator (2), an intermediate linear resonator (3), an output linear resonator (4) and an additionally introduced linear resonator (5), which are made in the form of rectangular waveguides shorted at the ends. The waveguides of the output resonator (4) and the additional resonator (5) are discretely coupled to each other in the regions of the maxima of the transverse component of the magnetic microwave field using several waveguide loops (6). The input of microwave energy (7) is located in the waveguide (2), and the output of microwave energy (8) in the waveguide (5). Along the waveguides (2), (3) and (4) are multi-row structures (9), (10), (11), formed by tape conductors (12), in which there are openings of the passage channels (13), the axes of which are perpendicular to the axes of the waveguides . The ribbon conductors (12) are located in the waveguides (2), (3) and (4) perpendicular to their axes and the axes of the passage channels (13). In the waveguides (2), (3) and (4) between the multi-row structures (9), (10), (11) there are reflecting electrodynamic elements (14). Vacuum-tight dielectric windows (15) and resonant diaphragms (16) are located in waveguide loops (6). The klystron also has an electron collector (17), pole pieces (18) of the magnetic focusing system, and magnets (19).

In electron guns (1), electron beams are formed that fall into the passage channels (13) of multi-row structures (9) - (11) and are focused by a longitudinal magnetic field, the configuration of which is determined by the pole tips (18) of the magnetic system. The input microwave signal is supplied to the input resonator waveguide (2) through the input of microwave energy (7) and excites in it an electromagnetic field of a standing wave of the type Nyup, which modulates electron beams in microwave gaps formed by tape conductors (12) of multi-row structures (9) speed. The speed modulation intensity will be proportional to (Qex), where Qex Pbx is the quality factor and the number of microwave gaps in the multi-row resonator structures (2), respectively. After passing through the cavity (2), the electron beams pass through the passage channels into the microwave gaps of the multi-row structures (10) of the intermediate cavity (3), where they are additionally modulated by velocity and grouped into bunches. In this case, the modulation intensity with respect to speed will be proportional to (Qex Pex} (Qnp Рпр), and the current modulation will be proportional to 7О

(Qex Рвх} (Qnp Рпр), where Qnp and Рпр are the quality factor and the number of microwave gaps in the multi-row structures of the resonator (3), respectively. From the resonator (3), the bunches fall into the microwave gaps of the multi-row structures (I) of the output resonator (4) Passing through microwave gaps, electron bunches in the resonator (4) excite an electromagnetic field with an intensity proportional to (Qebix Pout), where Qeux and Pout are the quality factor and the number of microwave gaps in the multi-row resonator structures (4), respectively. Therefore, the resulting gain of the klystron will be proportional to (Qex Qnp О okh) (Rvzh Rpr Rvykh) - Thus, the gain in a klystron with multi-gap linear resonators will be at the number of microwave gaps Pvkh, Rpr and Rvykh within 2-10 one or more orders of magnitude higher compared to the well-known multi-beam klystron (see prototype), in which due to the use of single-gap linear resonators (Рвх Рпр Рвяа 0, the gain is proportional (Qex Qnp Qebo) - Passing electron bundles passing through the microwave gaps of the multi-row structures of the output resonator (4) gradually slow down their kinetic energy to the microwave field . Therefore, to ensure a high electronic efficiency, it is necessary to reduce the distance between the ribbon conductors (12) in multi-row structures (11) according to the law, which ensures in the microwave gaps the fulfillment of the spatial-phase matching condition between the microwave field and electron bunches as they decelerate. From the waveguide of the output resonator (4), the electromagnetic field energy is partially transformed through the waveguide loops (6), in which the resonant diaphragms (16) and vacuum-tight dielectric windows (15) are located, into the waveguide of the additional resonator (5), from which

the net energy of the microwave field through the output of microwave energy (8) enters the load through the waveguide path. Spent electron clusters fall into collectors (17).

In the klystron, the input (2), intermediate (3), output (4) and additional (5) resonators can be made in the form of segments of a rectangular waveguide shorted at the ends. The dimensions of the waveguides of the resonators (2) - (5) provide excitation of the standing wave only of the type NNP in the operating frequency range. ), (3), (4) and (5), and the size of their narrow wall b must be equal to or less than a. The width of the ribbon conductors (12) in multi-row structures (9), (10), (11) should be less than 0.5 L, and the diameter of the region within which the openings of the passage channels are located should not exceed 0.25 L, where L. 25 (I / a) is the wavelength in the waveguide. Period L

A + d of multi-row structures (9), 10), (11) should be equal to or less than b IP, where is the required number of microwave gaps in a multi-row structure, d is the thickness of the ribbon conductors, and A is the length of the microwave gap. Moreover, the condition .QQ of the input (2) and intermediate (3) resonators must be satisfied for the given values of the wavelength I of the input signal and the accelerating voltage V on the resonators, the quantity Z ,, pc in multi-row structures

(9), (10) is determined from the expression / l (/ V / 505 (+ P) / P. In multi-row structures

(I) the output resonator (4) using this expression is determined by the L of the first microwave gap. For subsequent microwave gaps, L should decrease according to a certain law, for example, linear. The phase shift of the transverse component of the electric field in the microwave gaps of adjacent multi-row structures should be equal to (2k + l), therefore, multi-row structures should be located along the resonator waveguides with a period L ((A: + 0.5) L, where k 1, 2, 3, 4 is determined by the transverse dimensions of the electron guns (1) and the pole pieces (18) of the magnetic system.

The reflecting electrodynamic elements (14) in the waveguides (2), (3), (4) can be made in the form of segments of a rectangular waveguide having a length LO 0.5 L and transverse dimensions a and b0 0.56.

Energy input (7) can be made in the form of a T-shaped waveguide joint, in which a vacuum-tight dielectric window (15), made in the form of a cylindrical half-wave dielectric resonator, and a resonant diaphragm (16) are located. The input of energy (7) is advisable to arrange the input carefully in the middle of the waveguide

resonator (2) on its wide wall. In this case, the number A of multi-row structures (9), (10), (11) in the waveguides of the resonators (2), (3) and (4) should be even.

The resonator waveguide (5) has a length and non-uniform dimensions are the same as the resonator waveguide (4), but instead of multi-row structures (11), reflecting electrodynamic elements (20) are made in the form of segments of a rectangular waveguide. The length and non-uniform dimensions of these segments of the waveguide are chosen such that their transfer characteristic is equivalent to the transfer characteristic of multi-row structures (11).

The waveguide loops (6) are made in the form of segments of a rectangular waveguide, having a length f, n, α (2 / and + 1) L / 4 and the transverse dimensions a and b Q.5b, where m 1, 2, 3 are determined by the dimensions of the collectors ( 17) and pole pieces (18). The ends of the waveguides (6) are located on the wide walls of the waveguides of the resonators (4) and (5). The vacuum tight window (15) can be made in the form of a cylindrical half-wave dielectric resonator.

The output of microwave energy (8) can be made in the form of a T-shaped waveguide joint, which should be placed in the middle of the resonator waveguide (5) on its wide wall, the opposite wall, on which the waveguide loops are located (6).

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Claims (1)

A klystron containing electron guns, electron collectors, input and output of microwave energy, input, output and intermediate resonators in the form of rectangular waveguides, in which periodically, in the region of the maxima of the transverse component of the microwave electric field, microwave gaps with span channels for electron beams are located, whose axes are perpendicular to the axes of the resonator waveguides, and reflecting electrodynamic elements are located between the microwave gaps in the region of the maxima of the transverse component of the magnetic microwave field The fact is that the microwave gaps are made in the form of multi-row structures of tape conductors located perpendicular to the axes of the resonator waveguides and the axes of the span channels, and the microwave energy output is placed in the cavity additionally inserted into the klystron in the form of a rectangular waveguide, which is discretely coupled in the region of the maxima of the transverse component of a microwave microwave field with an output resonator waveguide through waveguide loops made in the form of a rectangular waveguide and containing vacuum-tight dielectric windows and resonance s aperture, and reflecting the electrodynamic elements are designed as segments of a rectangular waveguide whose narrow wall not less than half the narrow walls of the waveguides of the input, intermediate and output cavities.