Abstract: An electron beam deflection structure (10) of the traveling wave type effectively cancels the longitudinal voltage gradients and the associated electron beam defocusing that are characteristic of such deflection structures. The deflection structure comprises a first helical coil member (48) and a second helical coil member (50) that are coaxial with the longitudinal axis (26) of the tube. Each of the coil members has wide and narrow segments which alternate along the length of the coil in sequence with the turns of the coil. The first coil member has its wide segments (92a) positioned on the bottom and its narrow segment (92b) on top of the coil member. The second coil member has its wide segments (94a) positioned on top and its narrow segments (94b) positioned on the bottom of the coil member. The narrow segments from one of the coil members are interleaved with the wide segments from the other coil member.

Abstract: An electron beam deflection structure (10) of the traveling wave type includes first and second deflection members (52 and 58) positioned on opposite sides of and extending along the path of an electron beam (26) to deflect the beam in response to deflection signals applied to the deflection members. In a preferred embodiment, both deflection members are of a meander line type which include a plurality of deflection plate segments (74, 76) connected in series by a plurality of lead portions (78) to form a pair of transmission lines, each transmission line having a characteristic impedance that tends to vary with distance along the path of the electron beam due to a flared spacing between the output portions of the deflection members. Pitch compensation including different pitches for the first and second deflection members increases and maintains substantially uniform the characteristic impedance of each transmission line to prevent reflection of the deflection signal back toward the input end of the line.