Abstract: With re-synchronization included, dispersions and interaction impedances of some staggered double rectangular gating with various periods are calculated by CST, then beam-wave interaction of two W band traveling wave tube based on those structures is simulated by MTSS. The results show that one W band traveling wave tube based on two sections of staggered double rectangular gating with uniform period has output power of 48.92W~56.44W ,electron efficiency of 6.04%~6.96% and gain of over 49dB within 90~98GHz, meanwhile another W band traveling wave tube based on 7 sections of staggered double rectangular gating with various periods has output power of 57.06W~98W ,electron efficiency of 6.98%~11.99% and gain of over 50dB, and the improvement of electron efficiency is 1%~4%。