How to filter DC power line interference in a power line carrier PLC?

Filtering DC power line interference from power line carrier PLCs requires designing a filtering network based on the interference spectrum. A π-type filter is deployed at the DC input: a power inductor PWR6045R6R8M0T (6.8μH) is selected, and an electrolytic capacitor (100μF) is used in parallel with a ceramic capacitor (100nF) to filter low-frequency ripple. For high-frequency noise, a PBZ1608E600Z0T ferrite bead (60Ω@100MHz) is used in series. An LDO regulator is added at the power supply end of the sensitive circuit to improve the power supply rejection ratio. Simulation analysis of the filter's frequency response ensures attenuation greater than 40dB in the 10kHz-1MHz range. In actual testing, DC power supply noise measured with an oscilloscope should be less than 50mVpp. Filtering interference can improve carrier reception sensitivity by 10dB and increase communication distance.