Two Ways to Increase the Pulse Duration of the Solid Pulse-Forming Line Based on Dispersion Analysis

Solid dielectrics have been widely investigated as potential attractive candidates in compact portable pulsed-power systems. Slow-wave structure with good dispersion characteristics and broad transmission band can be used to increase the pulse duration while the size of pulse-forming line (PFL) decreases. In this paper, we present two different slow-wave structures, the tape helix for coaxial-line and the meander-line structure for the planar line, to increase the pulse duration of solid PFLs based on dispersion analysis. At first, the characteristic impedances, electric length, and dispersion curve of the PFL with the slowwave structure are calculated by the electromagnetic dispersion theory. Based on the theoretical calculations, the PFLs are designed and simulated by the electromagnetic field tool. Finally, some test results on the PFLs are introduced. Currently, both the Al₂O₃ (ε_r = 9.3) helical PFL and the glass-ceramic (ε_r = 225) meander-line PFL can deliver a pulsewith 50-ns width, of which the dimension is φ 67 mm × 305 mm and 95 mm × 95 mm × 4 mm, respectively.