Slotted Waveguide and Antenna Study for HPM and RF Applications

An S-band longitudinal slotted waveguide antenna was designed to perform as a uniform array. The antenna was investigated for its power handling capability. The input power threshold for both air breakdown and multipaction were studied. The radiation pattern measured in high power testing with a magnetron providing 500 ns long and 0.8 MW peak pulses, demonstrated good agreement with the simulated radiation pattern. This source power level was below the predicted maximum input power handling capability of 1.8 MW, at high elevation in Albuquerque, NM. No breakdown was observed during the experiment. To further reduce the size of the antenna array, a narrow-band, rugged, complementary-split-ring CSR slotted waveguide antenna SWA was designed and fabricated. Both simulation and experimental results showed that the complementary-split-ring slot radiates a linearly polarized wave with high efficiency. The CSR slotted waveguide antenna provided, approximately, 55 size reduction, compared to currently available SWA designs, with high directivity, low return loss, and very high power handling capability for S-band applications. Finally, a new approach to prototyping CSR-SWA antennas for high-power microwave applications by usinq 3D printing.