Design and experimental investigation of folded parallel-plate pulse forming line based on PCB

Using the FR-4 as the dielectric materials, a pulse forming line (PFL) module was developed by attaching five PCB PFLs in parallel. In order to optimize electric field distribution, a shielded electrode was inserted in the dielectric materials, and the theoretical analysis shows the shielded electron has no effect on the parameter and transmission characteristics of the PFL. The PFL can withstand more than 200 kV with a insulating layer thickness of 4 mm. According to the lifetime calculation equation, it is found that the PFL has a long lifetime when the charging voltage is 50-80 kV. The size of PFL module is 700 mm550 mm40 mm, and the characteristic impedance of it is 5.35 . When the PFL module is used in a Blumlein manner and charged to 50 kV, the output voltage on the match-load of 45 kV, full width at half magnitude (FWHM) of 140 ns, flat top of 75 ns and time rise of about 65 ns are obtained.