RU2706644C1 - Traveling-wave tube for linear amplifiers of communication satellite microwave power - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to microwave devices, mainly traveling-wave tubes (TWT). Traveling-wave tube comprises an electron gun, a magnetic focusing system, a decelerating system with input and output of microwave energy, with a passage channel for electron flow passage and a collector-recuperator of kinetic energy of electrons. Additionally, after the decelerating system with input and output of microwave energy, with a passage channel for passage of the electron flow, in front of the collector-recuperator of kinetic energy of electrons, TWT comprises a device for conversion into kinetic energy of electrons of the electron flux of microwave energy of microwave signals in the range of operating frequencies of the device, which include the frequency of the additional signal outside the range of working frequencies allocated for the communication channel and used for linearisation of characteristics of TWT in the mode of operation with high electronic efficiency. Conversion device consists of magnetic focusing system and section of delay system with input of microwave energy and transit channel for passage of electron flow, wherein period of said section of slowing system corresponds, at its operating voltage, mode of interaction in it of electron flow and electromagnetic wave passing in direction of collector-recuperator of kinetic energy of electrons, with increase of kinetic energy of electrons of electron flow due to conversion of microwave energy of microwave signals with frequency in range of operating frequencies of device, including the frequency of the additional signal outside the range of working frequencies allocated for the communication channel and the characteristics used for linearisation TWTL in operating mode with high electronic efficiency. Recuperation of obtained additional kinetic energy of electrons of electron flow in collector-recuperator allows reducing power consumption and increasing efficiency TWTL.

EFFECT: technical result is increase in efficiency factor TWTL in operating mode with high electronic efficiency and linearity of characteristics.

1 cl, 2 dwg

Description

The invention relates to electric vacuum microwave O-type devices, in particular, traveling wave tubes (TWT).

Known TWT containing an electron gun, a slowing down system with an input and output of microwave energy, a magnetic focusing system and a collector-recuperator of kinetic energy of electrons. [Handbook of Vacuum Electronics. Components and devices. // Edited by J. Eichmeier, M. Tamm. Translated from English by Е.Б. Makhiyanova edited by N.A. Bushueva. Moscow, ed. Technosphere. 2011. S. 39, 40.]. Such TWT has a high efficiency (50-70%) in the saturation mode of the output power, however, the nonlinearity of its characteristics in this mode does not allow the use of such TWT in amplifiers of communication systems with microwave signal modulation, which provides a high speed of digital information transmission. The compliance of the characteristics of such TWT with the necessary linearity requirements is ensured when it is used in these amplifiers in a substantially linear mode of operation - with an output power of 7-10 dB less than the saturation power. This leads to a decrease in the TWT efficiency by 3-5 times. In this case, the required TWT output power is achieved by increasing the electron flux power by a factor of 5–10, which leads to an increase in the electron flux current by a factor of 3–8, corresponding to an increase in the magnetic field induction amplitude of the magnetic focusing system, an increase in the overall dimensions of the TWT, and an increase in current collection density from the surface of the cathode and reduce the reliability of the TWT.

TWT is also known with a passive device connected between the region of conversion of the kinetic energy of the electron beam into microwave energy (slowing system) and the collector-recuperator of the kinetic energy of electrons. [H.G. Kosmahl (NASA) // Electron beam controller. U.S. Patent 3,764,850, MKI H01J 23/02. Published October 10, 1973]. In a passive device, the magnetic field of the magnetic focusing system is reduced, while the radius of the electron beam increases, the current density of the electron beam decreases, the transverse velocities of the electrons are partially converted to longitudinal and their non-laminarity is reduced, which improves electron energy recovery.

The disadvantages of this TWT are that the total energy of the electron beam in the passive device does not increase and that the characteristics of such a TWT with the necessary linearity requirements are also achieved in a substantially linear mode of operation - with an output power of 7-10 dB less than the saturation power.

Closest to the proposed invention is TWT, containing an electron gun, a slowing down system with an input and output of microwave energy, a magnetic focusing system, a collector-recuperator of kinetic energy of electrons, designed to operate with both single-signal and multi-signal amplification [Shalaev P.D. , Simonov D.L. The results of experimental studies of amplitude and phase modulation in a two-frequency mode of operation of a spiral TWT with high electronic efficiency // Saratov: Vestnik of SSTU. 2010. No3 (48). Issue 3. P. 99-105.], [Shalaev P.D., Simonov D.L. Reduction of nonlinear distortion of signals in O-type TWT in the operating frequency band of output amplifiers of microwave power of communication satellites // Radio Engineering. 2017. No. 7. S. 14-18.]. When an additional microwave signal is applied to the input of this TWT, a significant improvement in the linearity of its characteristics is achieved in the operation mode with high electronic efficiency. To this additional microwave signal does not violate the spectrum of operating frequencies in the communication channel, an additional microwave signal with a frequency outside the operating frequency band allocated for the communication channel is fed to the TWT input. The disadvantage of this TWT, as established as a result of the study of the TWT prototype [Shalaev P.D. Linearization of characteristics of microwave power amplifiers on TWT in high-efficiency modes using an unmodulated additional signal and energy recovery of a microwave electromagnetic field // Radio Engineering. 2018. No8. P. 187-191.], It is that with a significant improvement in the linearity of its characteristics in a non-linear mode of operation with an output power of 5-7 dB more power in a linear mode due to the supply to its input of an additional microwave signal with a frequency outside the allocated for the communication channel of the operating frequency band, the total TWT efficiency does not increase compared to the linear mode of its operation without supplying an additional microwave signal. This is due to the fact that part (up to 30%) of the TWT output power falls on the microwave output signal with a frequency outside the frequency band allocated for the communication channel and is not used, but is included in the total loss in the TWT. That is, up to 30% of the power of the electron beam is additionally spent on amplification of an additional microwave signal used to linearize the TWT characteristics (without taking into account the power of the combination components due to their comparative smallness).

The objective of the present invention is that the proposed traveling wave lamp for linear amplifiers of microwave power of communication satellites (TWL) should provide the ability to use the output power at the frequency of an additional input microwave signal to increase efficiency.

The technical result of the present invention is to increase the efficiency of the TWTL in the mode of operation with high electronic efficiency and linearity of characteristics.

The technical result is achieved by the fact that the traveling wave lamp contains an electron gun, a magnetic focusing system, a decelerating system with an input and output of microwave energy, with a passage channel for the passage of the electron beam and a collector-recuperator of kinetic energy of electrons. Additionally, after the slow-down system with the input and output of microwave energy, with a passage channel for the passage of the electron stream, in front of the collector-recuperator of the kinetic energy of electrons, the TWT contains a device for converting the electron kinetic energy of electrons into the electron flux of microwave energy of microwave energy in the operating frequency range of the device including the frequency of the additional signal outside the operating frequency range allocated for the communication channel and used to linearize the TWT characteristics in high-speed operation Kim electronic efficiency. The conversion device consists of a magnetic focusing system and a section of the slowdown system with an input of microwave energy and a passage channel for the passage of the electron beam, and the period of this section of the delay system corresponds, at its operating voltage, to the mode of interaction of the electron beam and the electromagnetic wave passing in it in the direction collector-recuperator of the kinetic energy of electrons, with an increase in the kinetic energy of the electrons of the electron stream due to the conversion of microwave energy microwave signal s with a frequency in the operating frequency range of the device, including the frequency of the additional signal outside the operating frequency range allocated for the communication channel and used to linearize the characteristics of the TWL in the mode of operation with high electronic efficiency. The recovery of the obtained additional kinetic energy of the electron flow electrons in the collector-recuperator can reduce the power consumption and increase the efficiency of the TWT.

The invention is illustrated by drawings:

in FIG. 1 - presents the TWT prototype, where:

1 - electron gun,

2 - magnetic focusing system,

3 - retarding system

4 - input microwave energy

5 - microwave energy output

6 - passage channel for the passage of the electron stream,

7 - collector-recuperator of the kinetic energy of electrons.

In FIG. 2 - presents TWL corresponding to the invention, where:

1 - electron gun,

2 - magnetic focusing system,

3 - retarding system

4 - input microwave energy

5 - output microwave energy

6 - passage channel for the passage of the electron stream,

7 - collector-recuperator of the kinetic energy of electrons,

8 - a device for converting into kinetic energy of electrons an electron stream of microwave energy of microwave signals,

9 - magnetic focusing system,

10 - section of the retarding system,

11 - input microwave energy

12 - passage channel for the passage of the electron stream.

A traveling wave lamp for linear amplifiers of microwave power of communication satellites contains an electron gun (1), a magnetic focusing system (2), a decelerating system (3) with an input (4) and an output (5) of microwave energy and a passage channel (6) for passing electron flow, a collector-recuperator of kinetic electron energy (7), additionally, after a deceleration system (3) with an input (4) and an output (5) of microwave energy and a passage channel (6) for the passage of electron flow, in front of the kinetic collector-recuperator electron energy (7), contains a device (8) converting the electron flux of microwave energy of microwave signals into the kinetic energy of electrons in the operating frequency range of the device, including the frequency of the additional signal in the TWL beyond the band allocated for the communication channel of the working frequencies used to linearize the characteristics of the TWL in the mode of operation with high electronic efficiency consisting of a magnetic focusing system (9), a section of the slowing system (10) with an input of microwave energy (11) and a passage channel (12) for the passage of the electron beam, I slow down with the period of this section system with its operating voltage corresponding to the mode of interaction of the electron beam and the electromagnetic wave in it, passing in the direction of the collector-recuperator of the kinetic energy of electrons, with an increase in the kinetic energy of the electrons of the electron stream due to the conversion of microwave energy of microwave signals with a frequency in the range of working device frequencies, including the frequency of the additional signal.

A traveling wave lamp for linear amplifiers of microwave power of communication satellites works as follows: an electron gun (1) creates an electron stream and accelerates its electrons to a speed Vep at the exit of the electron gun, the electron stream electrons from the electron gun enter the deceleration system (3) and move in its passage channel (6) to the collector-recuperator of the kinetic energy of electrons (7) with the velocity Vеу, the magnetic focusing system (2) creates a magnetic field that holds the electron flux at external boundaries less the span of the passage channel (6), in the input (4) from the external microwave path the input signals of the TWL are supplied, including an additional signal to improve the linearity of its characteristics, input (4) transmits the input signals of the TWL into the slow-down system (3), the electromagnetic waves of the input microwave The signals propagate along the retardation system (3) in the direction of electron flow of the electron beam with a velocity V microwave <V eu close to the velocity of the electron beam. In this case, the electron beam is modulated by density and the electrons are decelerated in regions with a higher density in the inhibitory phases of electromagnetic waves. As a result of the deceleration of electrons, their kinetic energy is converted into the energy of electromagnetic waves - there is an increase in the power of electromagnetic waves of input microwave signals (amplification). The amplified microwave signals through the output of the microwave signals (5) are transmitted to the output microwave path. Moreover, a part (up to 30%) of the output power of the TWLF falls on the output signal with the frequency of the additional signal outside the operating frequency band allocated for the communication channel. But the microwave output signal at the frequency of the additional signal is not used for the communication channel, is allocated from the spectrum of output signals, supplied, using the TWT prototype, to the load and dissipated in it in the form of heat. A part of the kinetic energy of the electron flux remaining after the transfer of their kinetic energy to amplified microwave signals, including an additional signal, is returned to the power source in the collector-recuperator of the kinetic energy of electrons (7) when electrons are braked in a constant electric field of its electrodes having potentials lower than the retarding potential systems (3). The microwave energy increased in the TWLF at the frequency of the additional signal increases the loss of the TWFL microwave energy, significantly reduces its efficiency due to an additional decrease in the kinetic energy of the electrons of the electron stream at the output of the slowing system (3) without returning the microwave energy to the TWFL at the frequency of the additional signal.

When using the TWFL proposed in the invention, the electrons of the electron density and velocity modulated electron density from the passage channel (6) of the retardation system (3) enter the passage channel (12) of the section of the retardation system (10) of the device (8) and move in the passage channel (12 ) to the collector-recuperator of the kinetic energy of electrons (7). Despite the difference in the electron velocity of the electron beam in the passage channel (12), in the areas of the electron beam with a higher electron density their velocities differ little from their average velocity Vэр. In this section, the electron density modulation in density is also preserved during the passage of electrons in the passage channel (12) of the device (8).

The magnetic focusing system (9) of the device (8) creates a magnetic field that holds the electron flux at the outer boundaries less than the boundaries of the passage channel (12),

Isolated in the output path from the spectrum of output signals, the output microwave signal at the frequency of the additional signal is fed to the input of microwave energy (11) of the device (8), and transmitted through the input of microwave energy (11) to the section of the slow-down system (10). The period of this section of the slowdown system, at its operating voltage, corresponds to the mode of interaction of the electron flow and the electromagnetic wave in it, passing in the direction of the collector-recuperator (7), with an increase in the kinetic energy of the electrons of the electron stream due to the conversion of microwave energy of microwave signals with a frequency in the operating frequency range of the device (8), including the frequency of the additional signal outside the operating frequency band allocated for the communication channel and used to linearize the characteristics of the TWT in the mode of operation with high electronic efficiency. An electromagnetic wave of the output microwave signal at a frequency of an additional signal propagates along the slowing-down system (10) in the direction of electron flow electron velocity with a velocity Vcwr> Vep close to the speed of the electron flow electrons with negative values of the desynchronism parameter or, alternatively, Vcwr <Vep close to the electron velocity of the electron beam with positive values of the desynchronism parameter corresponding to the regime of interaction of the electron beam and electromagnetic olny extending in a reservoir-heat exchanger (7) to transform the microwave energy wave into kinetic energy of the electron flow of electrons. As a result of such a conversion, the kinetic energy of the electrons of the electron stream in the passage channel (12) of the device (8) increases and more energy is returned to the power supply of the TWTL in the collector-recuperator (7). Such a sequential recovery of the microwave energy of the output microwave signal at the frequency of the additional signal in two stages: at the first stage in the device (8), the microwave energy is converted into the kinetic energy of the electrons, at the second stage in the collector-recuperator (7) this kinetic energy of the electrons is converted into the direct current energy of the power supply of LBVL, it allows to significantly (by 4-5% in absolute value) increase the efficiency of LBVL.

If necessary, the energy of signals of other sources of microwave signals in the operating frequency band of the device (8), for example, TWT prototypes, can also be recovered in the TWFL corresponding to the invention.

Information sources:

1. Handbook of vacuum electronics. Components and devices. // Edited by J. Eichmeier, M. Tamm. Translated from English by Е.Б. Makhiyanova edited by N.A. Bushueva. Moscow, ed. Technosphere. 2011.S. 39, 40.

2. H.G. Kosmahl (NASA) // Electron beam controller. U.S. Patent 3,764,850, MKI H01J 23/02. Published October 10, 1973.

3. Shalaev P.D., Simonov D.L. The results of experimental studies of amplitude and phase modulation in a two-frequency mode of operation of a spiral TWT with high electronic efficiency // Saratov: Vestnik of SSTU. 2010. No3 (48). Issue 3. S. 99-105.

4. Shalaev P.D., Simonov D.L. Reduction of nonlinear distortion of signals in O-type TWT in the operating frequency band of output amplifiers of microwave power of communication satellites // Radio Engineering. 2017. No. 7. S. 14-18.

5. Shalaev P.D. Linearization of characteristics of microwave power amplifiers on TWT in high-efficiency modes using an unmodulated additional signal and energy recovery of a microwave electromagnetic field // Radio Engineering. 2018. No8. S. 187-191.

Claims (1)

A traveling wave lamp for linear amplifiers of microwave power of communication satellites, containing an electron gun, a magnetic focusing system, a slow-down system with an input and output of microwave energy, with a span channel for the passage of electron flow and a collector-recuperator of kinetic energy of electrons, characterized in that it additionally after the slow-down system with the input and output of microwave energy, with a passage channel for the passage of the electron stream, in front of the collector-recuperator of the kinetic energy of electrons, contains a device converting the electron flux of microwave energy of microwave signals into the kinetic energy of electrons in the operating frequency range of the device, including the frequency of the additional signal outside the operating frequency range allocated for the communication channel and used to linearize the characteristics of a traveling wave lamp for linear amplifiers of microwave power of communication satellites in the operating mode with high electronic efficiency, consisting of a magnetic focusing system and a section of the retarding system with an input of microwave energy and a passage channel for I is the electron flow, and the period of this section of the slowing down system corresponds, at its operating voltage, to the interaction regime of the electron flow and the electromagnetic wave in it, passing in the direction of the collector-recuperator of the kinetic energy of the electrons, with an increase in the kinetic energy of the electrons of the electron flux due to microwave energy Microwave signals with a frequency in the operating frequency range of the device, including the frequency of the additional signal outside the operating range allocated for the communication channel This is used to linearize the characteristics of a traveling wave lamp for linear amplifiers of microwave power of communication satellites in a high electronic efficiency mode and recovering the additional kinetic energy of electrons of an electron stream in a collector-recuperator with increasing efficiency of a traveling wave lamp for linear amplifiers of microwave power of communication satellites .

Images