A High-Power $S$ -Band Waveguide Phase Shifter With Rotary RF Chokes

In this letter, a novel high-power microwave (HPM) phase shifter (PS) is proposed. The PS is based on the principle of tunable electrical length and can shift phase by turning a rotary choke piston in a toroidal-shaped phase-shifting segment. The simulation results show that the PS can shift phase linearly over 360 $^{\circ}$ in the frequency range of 2.7–2.9 GHz, the power handling capacity of this PS exceeds 450 MW, and the phase-shifting precision reaches 3.29 $^{\circ}$ / $^{\circ}$ at the central frequency. The cold test showed that the measured phase-shifting performance of the PS is in good agreement with the simulation results, furthermore, the PS can shift phase within 360 $^{\circ}$ in 30 ms, the return loss is higher than 12 dB, and the insertion loss is less than 0.4 dB.