Control of high power microwave radiation by electromagnetic band gap structures

A plasma control of powerful microwave propagation through the 1D and 2D EBG structures is investigated. Pulsed discharges in argon (or helium) at atmospheric pressure are applied as the plasma inhomogeneities. Temporal behavior of electron concentration in discharge is determined. The timedependent transmission spectra of 1D EBG structure formed solely by plasma in the X-waveguide are measured. The amplitudes of short (∼200 ns) powerful (50 kW) microwave pulses at frequency of 9.15 GHz are strongly suppressed (more than 40 dB) when they fall in the time interval of plasma structure existing. The propagation of these powerful microwave pulses through the triangle metallic 2D EBG structure with the plasma control elements is investigated too: when plasma acts as a compensator of defect in the front row of EBG structure the transmission in direction of 45 o quickly ceases (during a few tenth of nanoseconds), or one quickly arises, when plasma is as an additional defect.