Shaper nanosecond microwave pulses
(57) Abstract:Shaper nanosecond microwave pulses intended for the generation and formation of powerful microwave pulses mainly in radar and laboratory facilities for studying the influence of electromagnetic radiation on electronic equipment. The technical result of the development is the increase of the cross-section of the waveguides forming the element terminals of the resonator, and this solves the problem of an increase of the maximum pulse power output. Cumulative resonator contains an element of excitement, two segments of the waveguide and the output waveguide. A significant difference of development of the present invention is that the two waveguide segment are parallel and have a common longitudinal wall, shorting end walls are in the same plane, the open ends form a common open end, which coaxially with cuts docked waveguide, and the element excitation is a waveguide tee, attached by a longitudinal wall of their symmetric ples with the end walls of the segments, and they made a joint hole connection. 1 Il. The invention relates to techniques for microwave and is intended for generatemenu the effects of radiation on electronic equipment.The device operation is based on the resonant amplification of a field pulse supply of the microwave generator and the subsequent rapid output energy of the excited field of the resonant volume of the load. The output energy from the oscillator through a single-mode waveguides interference switch, performed in the T-shaped waveguide or coaxial coupling. Single-mode waveguides have a relatively small cross-sectional sizes, but in the process of excitation and output it through the full flow of energy, and thus it is an interference switch determines the dielectric strength and the maximum output peak power.It is known device for the formation of a powerful microwave pulses [A. N. Didenko, Y. G. Yushkov. Powerful microwave pulses of nanosecond duration. M, Energoatomizdat, 1984, S. 89-90] , in which the cumulative resonator made of a segment of a regular waveguide bounded from one end of the element excitation, and the other with a single-mode waveguide T-junction (tee). One leg of the tee shorted and it has a switch on the distancein/4 from the shorting end wall, whereinthe wavelength W of the tee and the same resonator and beyond for all kinds of vibrations, in addition to the H10.The disadvantages of the device include a small resonator, and as a consequence low-gain pulse power. For example, in the 3-cm wavelength range of the resonator, made of rectangular waveguides-section h mm2will have its own quality factor Q0not exceeding a few thousand that will not allow you to get gain, A more than 20. In addition, the maximum output power is limited. When filling the internal volume with air at atmospheric pressure critical tension Ekr= 30 kV/cm, which will correspond to the power traveling wave, as one of the two components of the standing wave, and equal output power Pkr= 0.45 MW.A well-known shaper of microwave pulses (patent N 1228256. Publ. 30.04.86, bull. N 16. Auth.: S. A. Novikov, S. C. Razin, Y. G. Yushkov), containing the HF generator and the cumulative resonator. The output resonator element made in the form of a waveguide tee with coaxial input and output shoulders. Lateral shoulder shorted and it has a switch. In waveguides tee may extend only a lower form of waves. Cumulative resonator made of handle types of oscillations. The input arm of the tee is connected to the coaxial resonator and the cross-section of the resonator from the tee smoothly reduced to the cross-section of the input arm of the tee. The resonator is excited at the lowest form of H10rectangular (or H11the round waveguide), and a smooth transition is fully consistent at the operating frequency.Due to the fact that part of the resonator is oversize, q 3-centimeter range reaches values of 104...1,2104and gain 40...50. However, this device also has a low value of the maximum output power. Conclusion energy occurs through single-mode waveguides - shoulder tee and the cavity filled with air at atmospheric pressure Pkr= 0.45 MW.Let us choose as a prototype microwave shaper [R. A. Alvarez, D. P. Byme. Prepulse supression of microware pulse compression cavity. Rev. Scient. Inst. v. 57, No. 10, Oct. 1986, p. 2475-2480], consisting of a microwave generator and cumulative resonator. Cumulative resonator element includes excitation, the output waveguide and cut two equal single-mode rectangular waveguide, in each of which one end is short-circuited, and the other is open. In one of the segments of the waveguide at a distance ofinThe device operates as follows. Exciting the microwave pulse from the microwave generator is supplied by the lateral shoulder in the E-plane. In the connections pane wave is divided between two pieces of waveguides, but these two waves, propagating along the segments toward zahratka, have opposite phases. The waveguide segments are of equal length, so the reflected wave to the field of connecting back with opposite phases. Therefore, in the output waveguide connected to the narrow side (H-plane) radiation does not occur. The amount of communication provided work a maximum value. At this point, is applied to the switch of the starting pulse voltage, and at a distance in/4 from shorting wall is formed independent of the microwave discharge. Plasma discharge causes the reflection of electromagnetic waves, wave phase, running from a segment of the waveguide containing the switch is inverted and side shoulders waves running towards each other, are in phase. Then folded waves are radiated in the shoulder, connected in H-plane, and fed to the load. The duration of radiation t0= L/Vgwhere Vg- the group velocity, L is the total length of the resonator.This device has a gain of two times greater than those of the asymmetric structure of the same length L, for reducing the time of the output energy. However, the limiting power output remains the same as in the above analogue of Pkr= 0,45 MW to 3-centimeter wavelength range when filling the cavity with air at atmospheric pressure. Limit the output power is limited to the same circumstance, the waveguides cumulative resonator and the output side in the H-plane are single-mode and in the specified range may have a cross-section h mm2.The proposed device, the driver of the microwave pulses, as the prototype contains a microwave generator and cumulative resonator composed of an element excitation, the output waveguide and the two segments of the waveguides of equal length, each with one side short-circuited, and the other is open and in one of the segments at a distancein/4 from takarajimasha wall placed switch. Unlike the prototype segments of the waveguide cumulative resonator parallel and have a common wall and are located so that the shorting end walls are in the same plane, and the open ends of the segments form a common open end of and coaxially with him with cuts docked output waveguide. The element excitation is made in the form of a waveguide tee, and coupled to the longitudinal wall of their symmetrical short-circuited shoulders with the end walls of the segments of the waveguides, which made a joint communication holes, and the side arm of the tee is connected to a microwave generator.Cumulative resonator of the device shown in the drawing.Exciting the resonator element is a waveguide tee formed lateral shoulder 1 and d is 7, forming a cumulative amount, have the same length, are parallel, and their shorting end walls are in the same plane 8. End shorting wall connected with a common longitudinal wall symmetrical shoulders 2 and 3 exciting tee and executed the communication holes 9 and 10. At a distance ofin/4 from shorting wall segment 6 posted by the switch and its control electrode 11. The open ends of the sections 6 and 7 form a common open end 12 and with him coaxially with the segments 6 and 7 is docked output waveguide 13.Consider the work on the example of the rectangular segments of the waveguides 6 and 7 having parallel wide walls. Then exciting tee is E-tee and the waves propagating along the shoulders 2 and 3 from the junction of the shoulder with input 1, have opposite phases. If Takoradi symmetrical shoulders 4 and 5 are located at a distance of in/2 holes, the segments 6 and 7 are excited by the magnetic field of the standing wave in the tee. Traveling wave in sections 6 and 7 also have opposite phases and cancel each other out in the General area of the open end 12 and at the input of the output waveguide 13. When performing the resonance conditions for the frequency of the exciting field miaimi loaded quality factor and the duration of the exciting pulse. At the end of the excitation process on firing electrode 11 switch start pulse in the transverse plane section of the waveguide 6 at a distancein/4 from the plane 8 is formed independent of the microwave discharge. Reflections on the discharge region to change a phase of a wave coming from the shoulder 6 to the input waveguide 13. Waves running from sections 6 and 7 will be formed in the waveguide 13 in the phase and in the volume of the resonator becomes associated with that load.The main difference between the designs is that the emerging wave is further propagated in the same direction. This allows to increase to some extent the cross-sectional area of the waveguide 6 and 7 and the output waveguide 13 in comparison with single-mode waveguides, the T-shaped coupling interference switch prototype and analogues. In the proposed device, there are no conditions for excitation of H20wave and the output waveguide can be made by section h mm2for frequencies of 10 GHz. The cross-section segments of the waveguides 6 and 7 can be even more, and the uniqueness of excitation of H10type of oscillation is determined by the resonant conditions. In the above example, in which besides the distance from the widely shared the aims of 1.35 MW, more than in the prototype and the like.Measurements of the layout of the device showed that crosstalk between the volume of the resonator and the output path during excitation at a frequency of 9.6 GHz 40 dB relative to the signal level in the cavity. Loaded q-factor in the critical mode of communication exceeds 9000 when the cross section of 20 x 40 mm2segments of the waveguide 6 and 7.In all the examples considered in real experimental conditions, the maximum power Pmaxmore of these values of Pkrby increasing the electric strength in pulsed fields and gas isolation of the inner volume. However, the ratio between the calculated values for analogues of the prototype and of the inventive device will be saved for the real modes, and in the inventive device maximum output peak power is 3 times more than in the prototype. Shaper microwave pulses containing microwave generator and cumulative resonator composed of an element excitation, the output waveguide and the two segments of the waveguides of equal length, each with one side short-circuited, and the other is open, and in one of the segments on russiancomrade, characterized in that the segments of the waveguides cumulative resonator placed in parallel have a common wall and are located so that the shorting end walls are in the same plane, and the open ends of the segments form a common open end of and coaxially with him with cuts docked output waveguide element excitation is made in the form of wave tee, and coupled to the longitudinal wall of their symmetrical short-circuited shoulders with the end walls of the segments of the waveguides, which made a joint communication holes, and the side arm of the tee is connected to a microwave generator.
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
FIELD: radio engineering, communication.
SUBSTANCE: microwave emission pulse is introduced to a waveguide section with gas-discharge lamps; glow discharges are lit in gas-discharge lamps by means of a pulse voltage generator, which leads to formation of a electromagnetic band structure. A device for reduction of duration of a microwave emission signal includes a waveguide section with five gas-discharge lamps, which is connected with one of its sides through a coaxial-waveguide transition and a ferrite valve to microwave generator output, and with the other side through a coaxial-waveguide transition and ferrite valve to a microwave detector; five gas-discharge lamps are located along the waveguide section perpendicular to its wide walls at interval l=Λ0/2÷Λ0, where Λ0=λ0(1-(λ0/2a)2)-1/2 - waveguide wave length, λ0 - length of incident microwave emission wave; a - size of wide wall of the waveguide section, and they are connected to the pulse voltage generator that is connected to the pulse generator output, the output of the synchronisation pulse of which is connected to the microwave generator.
EFFECT: reduction of duration of microwave pulses from tens of microseconds to tens of nanoseconds.
2 cl, 2 dwg