Numerical and Experimental Investigation of the Effects of Dimensional Parameters on Carbon-Nanotube-Coated Copper Plasma Limiter

The plasma limiter (PL) is a suitable method to protect electronic devices from high-power electromagnetic pulses. The
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-band PL has target specifications of 100 kW of power handling capability, < 100 ns of response time, and < 0.5 dB of insertion loss. Carbon nanotube (CNT) can be used to reduce power losses and instrument corrosion under frequent electromagnetic attacks. This article used CNT-coated copper needles in a PL to increase the electric field for the rapid breakdown process. Furthermore, the impact of dimensional parameters (needle’s length, needle’s radius, and axial displacement of the needles) were investigated. The experiment was conducted at 1800 W of peak power and 25 ns of the
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-band (2.45 GHz) microwave duration. In this case, the height of 19 mm and diameter of 1 mm were found to be the optimal needle parameters, in which the fastest breakdown of the electric field is available. The finite-element method was used by CST software to verify the experiment results. The transmission losses were < 5% in the normal state. The breakdown electric field threshold was ~431 kV/m near the atmospheric pressures. There was an error of < 1.28 in the case with the lowest compatibility.