Investigation of comb-type pulse forming line with low impedance

Development of pulsed power technology is toward higher power, longer duration, and more compact structures. Compact coaxial propylene carbonate pulse forming lines are widely used in the application of pulsed power systems. In order to further lengthen the duration and decrease the geometrical sizes of pulsed power systems, a comb-type pulse forming line is adopted. It is a slow-wave structure with a comb-type inner electrode. In this paper, the operation principle, theoretical analysis, numerical simulation, and experimental investigation of the comb-type forming line are carried out, respectively. First, the operation principle is briefly introduced. The principle to increase the duration is explained. Second, the theoretical analyses about the dispersion relation are proposed. Third, the PSpice model is built by the L-C network. Based on the calculated parameters, the electrical circuit is simulated. A Computer Simulation Technology (CST) model is also built, which allows for a straightforward coupling of electric and magnetic (EM) simulation and circuit simulation. Finally, the comb-type pulse forming line is experimentally tested and verified. For the comb-type propylene carbonate forming line with a 67 cm length to replace the traditional coaxial one, it has an impedance of 8 Ω and a duration of 64 ns. Experimental data on its test results are given. The experimental results are in accordance with the numerical simulations. The investigation approved the comb-type pulse forming line feasible and set a solid foundation for its application in the pulsed power system.