J. R. Mayes and W. C. Nunnally
The University of Missouri-Columbia
Columbia, Missouri 65211
The photoswitched Injection Wave Generator1,2,3 (IWG) is an alternate method of generating multiple cycles of microwave energy using parallel switches in a transmission line geometry that overcomes the limitations of the traditional and present day microwave sources. The photoswitches isolate initially charged transmission line segments from the output transmission line; with the simultaneous closure of the switches, the energy from the charged transmission line segments is released onto the output line in the form of pulses at spatial half wavelength locations.
The generator is limited by the switches used to generate the injected pulses. As neighboring pulses begin to overlap, the efficiency of the generator decreases and energy is shifted to the lower harmonics. This work studies the effect of switch material recombination time on the performance of the IWG. Four levels of Chromium-doped GaAs have been used for the switches, providing four unique recombination times. The generator has been tested at three operational frequencies for each material switch set.