A novel slow-wave structure, formed by placed one opposite the other plane impedance electrodes with zigzag configuration is described in this paper. To prevent the opposite-phase mode, vertexes of opposite zigzags are connected by metal straps. The sheet beam topology has the potential to significantly increase the output power of traveling-wave amplifiers at millimeter-wave frequencies and the small circuit period enables operation at relatively high voltages without the conditions for the backward-wave oscillation. The use of two or more zigzags in each electrode makes it possible widening e-beam tunnel. The dispersion characteristics of the connected zigzags are measured at different gaps between zigzags and at different gaps between them and the screen electrodes.