RU2520374C1 - Method for pulse length reduction of powerful shf radiation and method for its implementation - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: method for pulse length reduction of powerful SHF radiation and method for its implementation is characterised by introduction of SHF pulses into waveguide section with gas-filled tubes, under influence of downward powerful SHF radiation SHF-discharges are excited in the gas-filled tubes thus leading to formation of an electromagnetic band structure and pulse narrowing. The device for pulse length reduction of powerful SHF radiation contains a waveguide section with three gas-filled tubes connected by its one end through a coaxial transition and ferrite isolator to SHF-generator and by its other end through a coaxial transition and ferrite isolator to SHF-detector, the three gas-filled tubes are placed along the waveguide section perpendicular to its wide walls with distance l=Λ₀/2÷Λ₀, where Λ₀=λ₀(1-(λ₀/2a)²)^-1/2 is wave length in the waveguide, λ₀ is wave length of downward SHF-radiation; a is a size of the wide wall in the waveguide section.

EFFECT: reducing length of microsecond pulse of powerful SHF radiation up to 10 ns and less.

2 cl, 2 dwg

Description

The group of inventions relates to the field of microwave waveguide technology and can be used in radar technology.

A known method and device for generating powerful short microwave pulses [1], including the excitation of a low-power microwave signal, amplification and modulation of a microwave signal, selection of a signal with a carrier frequency f ₀ and phase φ ₀ , performing band-pass frequency and / or phase filtering of modulated The microwave signal, then the received signal is amplified and re-filtered, selecting a powerful signal with a carrier frequency f ₀ and phase φ ₀ .

Closest to the technical nature of the claimed invention are a method and apparatus for generating a microwave wave range emitted by short pulses [2]. The method consists in the formation of short pulses of microwave radiation from a continuous plasma laser ignition of a plasma formation in a waveguide section filled with a certain gas at low pressure, which causes a complete reflection of the incident microwave radiation and, accordingly, interrupt the transmitted microwave wave. The disadvantage of this device is that filling the waveguide section with gas at low pressure reduces its breakdown strength (waveguide) and laser radiation is used to ignite the plasma.

The objective of the invention is to reduce the duration of a microsecond pulse of high-power microwave radiation to 10 ns or less.

A method of reducing the pulse duration of high-power microwave radiation, in which a microwave pulse is led into a waveguide section with gas-filled tubes, microwave discharges are excited by incident high-power microwave radiation in gas-filled tubes, which leads to the formation of an electromagnetic strip structure and narrowing of the pulse, while the incident power Microwave radiation exceeds the necessary for microwave breakdown in the tubes.

A method of reducing the pulse duration of high-power microwave radiation is implemented using the device.

A device for reducing the pulse duration of high-power microwave radiation, containing a waveguide section with three gas-filled tubes, one side through a coaxial waveguide junction and a ferrite gate connected to the output of the microwave generator, and the other side through a coaxial waveguide junction and a ferrite gate, to a microwave detector, three gas-filled tube sections are arranged along the waveguide perpendicular to its wide wall with period l = Λ _{0/2 0} ÷ Λ where Λ ₀ = λ ₀ (1- (λ _0/2 a) ^{2) -1/2} - the wavelength in the waveguide , λ ₀ - wavelength pa giving microwave radiation; and - the size of the wide wall of the waveguide section.

The essence of the device is illustrated in figure 1, where:

1 - waveguide section;

2 - coaxial waveguide transition;

3 - ferrite valve;

4 - microwave generator;

5 - microwave detector;

6 - gas-filled tube.

According to the invention, the output of the microwave generator 4 through the valve 3 and the coaxial waveguide transition 2 is connected to the waveguide section 1. The microwave signal from the waveguide section 1 through another coaxial waveguide transition 2 and the valve 3 is supplied to the microwave detector 5. Gas-filled tubes 6 are installed along the waveguide section on its axis perpendicular to the broad walls with period l = Λ _{0/2 0} ÷ Λ where Λ ₀ = λ ₀ (1- (λ _0/2 a) ^{2) -1/2} - the wavelength in the waveguide, λ ₀ - length waves of incident microwave radiation; and - the size of the wide wall of the waveguide section.

The device operates as follows.

Microwave radiation from the microwave generator 4 is supplied to the waveguide section 1, passed through it, and registered by the microwave detector 5. Under the influence of the incident powerful microwave radiation in gas-filled tubes 6, plasma columns appear that occupy the space between the wide walls of the waveguide section, which leads to a sharp decrease in the duration of the transmitted pulse .

In the practical implementation of the model, a rectangular waveguide with a cross section of 23 × 10 mm ^2, about 50 cm long ^, and incident microwave radiation with a wavelength in air of λ ₀ = 33 mm was used. Three gas-filled tubes (length of at least 15 mm, inner diameter of 3 mm, filled with neon at a pressure of 70 mm Hg) were perpendicular to the wide walls of the waveguide section in holes with a diameter of 4 mm drilled at a distance l = 38 mm from each other in the middle broad wall that corresponds to the range ₀ l = Λ / 2 ₀ ÷ Λ = 24 ÷ 48 mm. When you turn on the microwave generator 4 under the influence of incident microwave radiation with a power of 20 kW and a pulse duration of 200 ns (Fig. 2, curve 1), plasma columns appear in gas-filled tubes 6, and the duration of the transmitted microwave pulse is sharply reduced to 10 ns (Fig. 2, curve 2).

Using the invention allows to reduce the duration of a microsecond pulse of high-power microwave radiation.

Information sources

1. RU 2210857.

2. RU 2188500.

3. Control of electromagnetic band gap devices by discharge plasmas / V.I. Arkhipenko [et al.] // Proceedings of the VIII International Workshop on Microwave Discharges: Fundamentals and Applications (MD-8), Zvenigorod, Russia, 10-14 September 2012 / Sci. Council of RAS on Physics of Low Temperature Plasma; ed. Yu.A. Lebedev. - Moscow: Yanus-K, 2012 .-- P.275-280.

Claims (2)

1. A method of reducing the pulse duration of high-power microwave radiation, in which a microwave pulse is led into a waveguide section with gas-filled tubes, characterized in that under the influence of incident high-power microwave radiation in gas-filled tubes, microwave discharges are excited, which leads to the formation of an electromagnetic strip structure and narrowing pulse, while the power of the incident microwave radiation exceeds the necessary for microwave breakdown in the tubes. 2. A device for reducing the pulse duration of high-power microwave radiation by the method according to claim 1, containing a waveguide section with three gas-filled tubes, one side through a coaxial waveguide transition and a ferrite gate connected to the output of the microwave generator, and the other side through a coaxial waveguide transition and ferrite valve - a microwave detector, characterized in that three gas-filled tube sections are arranged along the waveguide perpendicular to its wide wall with period l = Λ _{0/2 0} ÷ Λ wherein Λ ₀ = λ ₀ (1- (λ _0/2 a) ² ) ^1/2 - length waves in the waveguide, λ ₀ is the wavelength of the incident microwave radiation; and - the size of the wide wall of the waveguide section.

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