SU139021A1 - Microwave electron beam amplifier on a BOV or TWT with feedback - Google Patents

Description

Known electronic microwave amplifiers for traveling or reverse wave tubes (BWO or TWT). The main disadvantage of such amplifiers is that they have a relatively low gain (up to 35-45 dB). If it is necessary to have amplifiers with significantly higher gains (up to 100 db), it is necessary to sequentially turn on several amplifiers, which significantly complicates the design of the device, increases its dimensions, weight, power supply, etc.

In the described microwave amplifier for BWO or TWT, a high gain is obtained by using a sun-regenerative mode of operation. Such a mode can be obtained in several ways, for example, by applying a signal from an external generator with a frequency 100-10000 times lower than the frequency of the signal being amplified between the cathode and one of the gun electrodes. The amplitude of this signal must be sufficient to modulate the beam current around the trigger value. Another way to obtain the superregenerative mode is that one of the axially symmetric electrodes of the gun is made in the form of two identical halves, electrically isolated from each other. These electrodes are supplied from an external source with an unforgettable potential difference that causes periodic deviations of the electron beam. The same mode is established if a magnet coil is installed near the shell of the lamp, through which a periodically varying current is passed.

A schematic diagram of a super regenerative amplifier on a traveling-wave tube with external feedback is shown in FIG. 1. In FIG. Figures 2 and 3 show the amplifiers on a traveling-wave tube, in which high-frequency voltage is applied to the gun electrode, respectively, periodically deflected, an electron beam, and an additional electrode.

Between the cathode 1 and the collector 2 of the traveling-wave tube (Fig. 1) are located the electrodes of the gun 5 and the retarding system 4. For Osul 139021-2

A high-frequency generator 5 serves as the superregenerative mode of operation of the amplifier. The feedback is carried out through a feedback filter. The voltage from the high-frequency generator is supplied to the electrode of the gun, which periodically changes the current of the electron beam (Fig. 1), or to the electrode of the gun, which periodically deflects the electron beam (Fig. 2). The electron beam can also be deflected using an additional electrode 7 (Fig. 3), which is also supplied with voltage from the generator 5. The electrode 7 is located near the slowing-down system 4.

The superregenerative mode can also be established by locating a magnetic coil near the lamp shell, which is supplied with voltage from a high-frequency generator. A change in the current flowing through the magnetic coil will cause a change in the position of the electron beam, and hence the degree of regeneration.

When using a reverse wave lamp as an amplifying lamp, the same methods are used to provide the super regenerative mode as in the devices shown in FIG. 1, 2 and 3. In addition, a similar operation mode is achieved if the accelerating voltage is periodically changed within a small range. However, the beam current must exceed the starting current by a small amount (on the order of 5-10%). Such a device provides amplification in a wide frequency band.

The described microwave amplifiers on the TWT or BWO provide amplification up to 100 dB.

Subject invention

Electron-beam microwave amplifier for BWO or TWT with feedback, characterized in that, in order to increase the gain and working frequency band by using the superregenerative mode, it between the two halves of one of the axially symmetric gun electrodes or between the cathode and the focusing electrode , or between the cathode and an additional electrode, or a high-frequency voltage from an external generator is applied to the magnetic coil, providing a periodic change or beam current near the starting value , Or the velocity of the electrons, or their trajectories.

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