Design for high power and low impedance triplate transmission line

A low impedance triplate transmission line, consisting of three parallel plate-electrodes, filled with de-ionized water, was designed for the Z-pinch Primary Test Stand (PTS) prototype. The determination of the triplate line’s parameters by its characteristic impedance cannot use the traditional bi-plate impedance formula, since the coupling-capacitance between the inner plate edge and water tank must be considered. The rated impedance of the triplate line was 4.00 Ω, and the designed impedance reached 4.08 Ω by the dimension of the triplate line without water tank. When considering capacitance coupling between triplate edge and water tank, the triplate line’s impedance was 3.77 Ω by precise FEM calculation. While, the actual operation impedance was 3.83 Ω according to measured volt