CN Type A is a versatile coupling network that allows manual switching between AC and DC configurations, enabling the injection of RF test voltage in common mode to the signal and control ports of the EUT. Covering the frequency range from 0 Hz to 150 kHz, it simulates electromagnetic interference (EMI) conditions in both AC and DC environments. In compliance with IEC/EN 61000-4-16, this coupling network ensures a reliable and comprehensive method for testing the immunity of devices with input/output and control lines. An additional decoupling transformer is required to protect auxiliary equipment from the test voltage. With its manual switching capability, CN Type A is ideal for testing devices that operate in both AC and DC systems, providing flexibility and ensuring consistent performance under varied EMI conditions.