Investigation and evaluation of two new non-planar ladder derived delay lines

Ladder lines comprise simple, mechanically rigid, and easily fabricated periodic structures. Planar ladders have a limited bandwidth. Two new non-planar ladder-derived delay lines, the X-line and the skew-bar line are discussed. The X-line may be considered as two intersecting planar ladder lines, while the skew-bar line is a twisted planar ladder line. ωβ-diagrams have been measured revealing two pass bands for the X-line. In addition, the effect of various parameters such as the angle between adjacent bars, the period, and the ratio of the beam aperture and the bar length have been studied.