Design and RF Characterization of W-band Meander-Line and Folded-Waveguide Slow-Wave Structures for TWTs

Studies on design and RF characterization were carried out for two different types of slow-wave structures (SWS) at W-band frequencies: 1) a meander-line SWS along with step impedance transformer, and 2) a folded-waveguide slow-wave structure along with tapered waveguide coupler. Quasi-TEM analysis was used for the design of these structures and the structures were fabricated using wire-cut and spark-erosion electric discharge machining. Dispersion characteristics and S-parameters of the structures were measured and compared against those obtained from analysis and 3-D electromagnetic simulation using CST-microwave studio.