Plasma switch for X-band active SLED-II RF pulse compressor

As proposed by SLAC, the efficiency of a pulse compressor of the SLED-II type could be increased by changing both the phase of the microwave source and the coupling coefficient of the delay line during the input pulse. In the existing SLED-II system the resonant delay line is coupled with the source via an iris with a constant reflection coefficient. Replacement of the iris with an active component makes it possible to create an active SLED-II system. In this paper use of a plasma switch as the active element is discussed. Experiments with a compression system that consisted of the plasma switch and a 6-m resonant delay line with round trip power losses of 1.5% showed that it is possible to achieve the following parameters for an active 11.4 GHz SLED-II compression system: compression ratio C = 10 - 16, power gain M = 7 - 12, and compression efficiency eta = 65 - 75%.