Robust High Average Power Modulator

Some DOE modulators have been under development for a decade, but do not yet meet the specifications for voltage, droop, or pulse width. A fundamental design limitation is that the inverters switch the full current 30 times during each pulse, requiring large and expensive switching transistors. A new architecture was invented, consisting of an SCR-controlled power supply, a solid-state modulator, and a small droop corrector. The droop corrector effectively gives the capacitor in the modulator an infinite capacitance. The system will meet the droop specifications, is inherently reliable, and will cost only $1.1 M instead of the present $1.7 M. This is because (1) the modulator switches only once per pulse, (2) the droop corrector switches only 5% of the power at high frequency, (3) The SCR-controlled supply is inexpensive, and (4) there is no output pulse transformer. The droop corrector is the new element for this SBIR. In Phase I the maximum voltage and device temperature for the corrector was verified, and the switching control scheme was developed. In Phase II the droop compensation supply and the modulator will be designed and built. The testing will be done with a low-power supply. This hardware will be delivered to a suitable laboratory for testing and evaluation. The cost data will be collected as the system is built, and accurately estimate the future production costs. Commercial Applications and Other Benefits: The technology developed under this SBIR will apply to other high-power long-pulse modulators, such as those found in particle accelerators and radar transmitters.