High-power squeeze-type phase shifter at W-band

We describe the design, fabrication, and bench study of a millimeter-wave phase shifter employed as a high-power recirculator for a traveling-wave resonator circuit. The oxygen-free electronic-grade copper phase shifter was prepared by electrodischarge machining. Measured phase-shifter characteristics are presented and compared with theory. The phase shifter was employed in a traveling-wave circuit at 91.4 GHz with a circulating power of 0.2 MW and subjected to fields greater than 10 MV/m without evidence of breakdown.