A high-efficiency wideband coupler for nanosecond-level pulsed current injection.

Area of Science:

• Electromagnetic Compatibility (EMC) Engineering
• Electrical Engineering
• Materials Science

Background:

• Pulsed Current Injection (PCI) is a critical technique for testing equipment vulnerability to nanosecond-level Transient Electromagnetic Disturbances (TEDs).
• Existing inductive couplers struggle to efficiently inject wideband disturbances, limiting the effectiveness of PCI testing for various TEDs like EMP, VFT0, and EFT.
• The wide frequency spectrum of TEDs necessitates improved coupling mechanisms for accurate vulnerability assessments.

Purpose of the Study:

• To propose and validate a high-efficiency, wideband PCI coupler for enhanced conducted vulnerability testing.
• To address the limitations of existing couplers in efficiently interacting with equipment under test (EUT) across a wide frequency range.
• To improve the injection of proper disturbances at EUT ports during PCI tests.

Main Methods:

• Theoretical analysis of coupling performance using a distributed-parameter model of an inductive coupler.
• Enhancement of inductive coupling through the use of composited ferrites instead of simplex Ni-Zn ferrites.
• Improvement of high-frequency performance by enhancing capacitive coupling via distributed tubular winding.
• Experimental validation of a prototype PCI coupler (30 × 10 × 10 cm³).

Main Results:

• The developed PCI coupler demonstrates significantly enhanced coupling performance over a wide frequency band.
• The use of composited ferrites and distributed tubular winding improved both inductive and capacitive coupling.
• Experimental results show a substantial improvement in the 3 dB bandwidth, increasing from 421 kHz–14 MHz to 77 kHz–39 MHz.
• The validated coupler is effective for the frequency ranges relevant to PCI testing.

Conclusions:

• The proposed high-efficiency wideband PCI coupler effectively overcomes the limitations of existing technologies.
• The enhanced coupler enables more accurate and efficient vulnerability testing of electronic equipment against a broader spectrum of TEDs.
• This advancement is crucial for ensuring the electromagnetic compatibility and resilience of EUTs in diverse operational environments.