A High-Power Waveguide Phase Shifter With Periodic RF Chokes for Subgigawatt Nanopulse Transmission

A high-power handling waveguide phase shifter with a high RF leakage attenuation is proposed at S-band. It uses the periodic RF chokes as a moveable noncontacting short circuit and a compact narrow-wall hybrid coupler in order to improve the RF leakage attenuation and the power handling capacity in low-profile beam-forming networks, respectively. This geometry is attractive, since it does not need a capacitive loading button and a contacting short circuit, which reduce the power handling capacity of the phase shifter. The results shows that the phase shifter could handle the high-power pulse energy of subgigawatt levels, and the phase can be adjustable in a range of 0°-360° over the 0.5-GHz bandwidth for -15-dB return loss in a numerical simulation. In addition, it has a high RF-leakage attenuation of -110 dB, which is a significant improvement compared with that of the single RF choke of -50 dB over the frequency range of 2.7-3.2 GHz.