Microwave energy compression using a high-intensity electron beam switch

Abstract

Stored microwave energy has been released using a high-intensity electron beam switch. Experiments using this switch have produced energy compression at room temperature and pulses as short as several nanoseconds. Here we discuss the experimental results and the underlying theory.

Two-channel 100-MW microwave compressor for the three-centimeter wavelength range

“…1. View of a two-channel compressor: microwave oscillator (1), matched load (2), 3-dB directional coupler (3), first channel of the compressor (4), second channel of the compressor (5), TE 01 -mode converter (6), input and output electrically controlled reflectors (7), storage cavity (8), reflector (9), and phase rotator (10).…”

“…In the centimeter wavelength range, the operation of studied switches is based on various principles, such as variation in the dielectric permittivity (conductivity) of semiconductors affected by optical radiation [7,8], creation of a plasma in the switch [6,9], or use of an electron beam [10]. Currently, the best results have been obtained for plasma-switch compressors [6], although the achieved parameters are still far from those required for use in accelerators.…”

“…This method is based on energy storage in a high-Q microwave cavity and the subsequent rapid increase in the cavity coupling with the load (Q-factor modulation) by means of a special fast-acting switch. This method is attractive due to the possibility of obtaining high power gains (about [10][11][12][13][14][15]) and a small size of the storage cavity (the typical dimension is about 1 m).…”

High power activeX-band pulse compressor using plasma switches

“…Each channel is a singlechannel compressor excited in the TE 01 mode of a circular waveguide. The channel includes a TE 10 rectangular to TE 01 mode converter (6), which is connected via a smooth transition to the storage resonator formed by an electrically controlled reflector (7) and circular-waveguide section (8) with an overcritical narrowing at its end (9). The central part of the cavity for storing microwave energy is a section of an oversized 110-cm-long waveguide 80 mm in diameter, which is equipped with a tapered 40-cm-long transition to a narrower waveguide.…”

“…Operation of switches considered for application in the cm-wave band is based on several distinctive approaches, including: (1) changes in the dielectric permittivity (i.e. rf conductivity) of semiconductors, caused by incident pulsed optical radiation [5,6]; (2) generation of pulsed plasma in the switch [7,8]; and (3) injection of a pulsed electron beam [9]. Switching based on changes in magnetic permeability is usually not considered practical, due to the inherent slow switching time of most magnetic circuits.…”