How to rectify the non-compliance of conducted emission from a power DTU?

To rectify conducted emissions failures in a DTU (Distributed Transmission Unit), the noise source must be located and filtering strengthened. Use a spectrum analyzer combined with a current probe to pinpoint the noise source at the excessive frequency, such as the switching power supply or clock circuit. For the excessive frequency, add a common-mode inductor CML4532A-510T or a ferrite core at the power input. Adjust the X capacitor value, for example, increasing it from 0.1μF to 0.47μF. Check the grounding system to ensure low impedance. After rectification, retest; conducted emissions should be at least 6dB below the limit. Common rectification measures also include adding shielding and optimizing PCB layout. Systematic rectification can ensure the product passes the conducted emissions test, avoiding time-to-market delays.