Coherent summation of Ka-band microwave beams produced by sub-gigawatt superradiance backward wave oscillators

Abstract

Coherent summation of microwave beams has been demonstrated for two superradiance Ka-band backward wave oscillators producing over 700 MW of power. The explosive emission cathodes of the e-beam injectors were powered by stable splitted voltage pulses produced by an all-solid-state modulator. The voltage fronts were shortened to 300 ps in controlled delay shock-excited ferrite lines. The standard deviation of the phase difference between the microwave pulses was less than 2% of the oscillations period. The power flux density of the summarized radiation was the same as that of a single generator producing an output power of ∼3 GW.

Coherent Summation of Emission From Relativistic Cherenkov Sources as a Way of Production of Extremely High-Intensity Microwave Pulses

“…In experiments with coherent summation of the emission from two-channels Ka-band superradiative oscillators [28] we demonstrated high stability of the phases (~2% standard deviation). The radiation power density with a single oscillator of power 700MW was equivalent to ~ (700MW x 2 2 ) ≈ 3 GW for the two phased synchronised oscillators.…”

Simulative research on reverse current in magnetically insulated coaxial diode

“…Even though the reverse current loss is avoided when the reverse electrons strike on the shield hoop in the diode, the appearance of reverse current that shunts the useful forward current is especially critical in cases where the beam is used for in-phase excitation of several HPM oscillators. [8][9][10][11] However, the MICD model generally does not take the cathode shank emission into account [12][13][14] and ignores the reverse current. References 1,2 discussed the reverse current in a weak guiding magnetic field when the electron beam is dispersed, which is inconclusive.…”

Gyromagnetic nonlinear transmission line generator of high voltage pulses modulated at 4 GHz frequency with 1000 Hz pulse repetition rate

“…Multichannel microwave sources [1][2][3][4][5][6][7] considerably increase a power flux density of rf-emission in the far-field region of the major maximum of the directional pattern (DP) and sharpen a beam [1][2][3]. Maximum increase in the flux power density is quadratic to a quantity of sources.…”

“…Maximum increase in the flux power density is quadratic to a quantity of sources. So, it is clear that there is an interest in the systems when a power of every channel reaches hundreds of megawatts and higher [1][2][3][4][5]. The on-line control of delays of the output pulses allows an adjustment of the mutual phasing [5][6][7] permitting the integral DP scanning in space.…”