SBIR-STTR Award

High-Power Microwave fields between 500 MHz and 1 GHz can upset electronic equipment at a considerable distance. However, it remains challenging to find a suitable high-power microwave source for such fields. Such devices should have a bandwidth of 10-15%, reasonable efficiency, low cost, compact size, and peak power of about 1 GW. Existing sources, such as magnetrons, are both massive and expensive. Another source, the switched oscillator, is too small to store sufficient energy. Therefore, we propose developing a Microwave Pulse Compressor (MPC). Such devices are commonly used at particle accelerators at frequencies between 10 and 30 GHz, but they could be adapted to 500 MHz to 1 GHz. MPCs require only a medium-power source to drive them, so they have modest size and weight. MPCs can be built much larger than switched oscillators, so they can store much more energy. During Phase I we will design both a low-power and high-power version of the MPC. We will build the low-power version during Phase I. We will design the high-power version to operate somewhere within the frequency range of 500 MHz to 1 GHz, to be decided in consultation with AFRL, to be built in Phase II.

Keywords:
HIGH POWER MICROWAVES (HPM), MICROWAVE PULSE COMPRESSOR (MPC), RECTANGULAR WAVEGUIDE, COAXIAL TRANSMISSION LINE, MAGNETRON, SWITCHED OSCILLATOR, MICROWAVE WEAPON

High-Power Microwave fields with frequencies near 1 GHz have been shown to upset electronic equipment at a distance. The challenge lies in finding a high-power source that provides a pulse of continuous-wave power 20-30 ns in length, with reasonable efficiency, low cost, small size and mass, and peak power approaching 1 GW. Existing sources for this application include magnetrons and switched oscillators. Magnetrons require either large magnets or large Helmholtz coils that require massive power sources. Switched oscillators are too small to store sufficient energy. To address the shortcomings of existing sources, we propose developing a Microwave Pulse Compressor (MPC), which uses a resonant cavity to compress and amplify the power from a source with moderate power. When a spark fires across a shorting switch, the resonance condition of the cavity is lost, causing the cavity to dump its high-power output. MPCs require only a microwave source with modest power to drive them, so they have modest size and weight. MPCs are larger than switched oscillators, so they can store more energy. We will base our compressor on the Nessie source, resulting in a peak power of 350 MW for 20 ns, with a repetition rate of 400 Hz.

Keywords:
High Power Microwaves (Hpm), Microwave Pulse Compressor (Mpc), Rectangular Waveguide Cavity Resonator, Magnetron, Switched Oscillator, Microwave Weapo