Abstract: For E-band broadband applications, a novel slow-wave structure suitable for broadband traveling wave tubes is proposed: the elliptical bending folded waveguide. Compared to the traditional folded waveguides, this design modifies the original straight waveguide sections into elliptical structures and introduces an inclined angle to the straight waveguide sections, thereby achieving better broadband performance. Using electromagnetic simulation software CST, the effects of various parameters of this new slow-wave structure on the phase velocity ratio and coupling impedance are analyzed. In the frequency range of 71 GHz~96 GHz, the elliptical bent folded waveguide structure, compared to conventional folded waveguide structures, achieves a 77% increase in the difference of phase velocity ratio while only reducing the coupling impedance by 3.8%, significantly improving broadband performance.