Planar meander lines have been recently studied
in detail due to their favorable properties as slow wave
structures for traveling wave tubes. However, the
interaction of a cylindrical electron beam with this kind of
structures is not efficient enough in order to achieve the
output power levels required for space applications at Wband. A new design, suitable and optimized for the
cylindrical beam geometry, is introduced in this work. Cold
and large signal results are presented in the paper.