A virtual-cathode reflex triode for high-power microwave generation

Abstract

Articles you may be interested inHigh power microwave generation from coaxial virtual cathode oscillator using graphite and velvet cathodes

Feasibility Study of Axially- Extracted Virtual Cathode Oscillator

“…The reason for this bunching is ∂ω/∂E<0 [7]. This nonisochronic mechanism is similar to that of the electron cyclotron maser.…”

“…During the electron beam pulse length, there can be a substantial variation in the electron density, and subsequently causes a large change in the oscillation frequency [7]. The frequency usually sweeps from a low to high value during the pulse, because the electron beam current increases due to the partial electron beam diode impedance collapse (closure) [2,4,7,24].…”

“…As a result of the positive potential on the anode, the electrons do not leave the system but rather oscillate between the real and virtual cathodes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The microwave emission is attributed to the phase bunching of the oscillating electrons inside the potential well of the system [2][3][4][5][6][7].…”

“…The virtual cathode oscillators have been built in two basic geometries. In one configuration, the microwave extraction is perpendicular to the electron beam (radial extraction), and the other configuration is axially symmetric, the microwave power is extracted in the same direction as the electron beam (axial extraction) [4,5,7]. The tunability of the radiation frequencies in virtual cathode oscillator can be achieved by changing the anode-cathode gap spacing, cathode dimensions and shape, and anode voltage with respect to cathode voltage [19].…”

“…Among the several types of pulsed high-power microwave generators, the virtual cathode oscillator has been considered very attractive because of its conceptual and mechanical simplicity, high output power capability [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and possible wide-bandwidth with frequency tunable characters which make it attractive for applications where the highpower and wide-bandwidth is acceptable. This device is based on a special class of the bremsstrahlung radiation of the relativistic electrons oscillating axially in the electrostatic fields [4,5].…”