Ridge-loaded ladder lines

The Karp structure, anti-Karp structure, and ridge-loaded stub-supported meander line have been analyzed by the Fletcher method and curves of dispersion and interaction impedance are given which are sufficiently comprehensive for most design purposes. The results of measurements on an anti-Karp structure and a ridge-loaded stub-supported meander line are given for comparison with the analysis. The relative merits of the three structures for both forward and backward wave interaction at medium and low voltages are discussed in some detail, and it is concluded that the use of a structure which propagates in the absence of a ridge permits the achievement of greater bandwidth in low voltage BWO's and gives greater design flexibility. It is also shown that the structures may, without significantly altering their circuit properties, be deformed into shapes suitable for use with annular or solid circular beams.