How to separate the signal ground and power ground in a power line carrier PLC?

The design of power line carrier PLC signal ground and power ground separation must adhere to the single-point connection principle to prevent noise coupling. On the PCB layout, signal ground (analog ground, digital ground) and power ground (power supply ground, motor drive ground) should be physically separated to form independent ground plane areas. The separation spacing should be at least 2mm to avoid copper foil overlap. The single-point connection point should be selected at the power input or below the ADC conversion chip, using a 0Ω resistor or PBZ1608A-102Z0T ferrite bead to provide a DC path while suppressing high-frequency noise. The signal ground plane should be complete to avoid interrupting the signal return path due to separation. The power ground plane needs to be wide enough to carry large currents. Ground plane impedance should be analyzed through simulation to optimize the separation shape and ensure signal integrity. In actual testing, the ground noise voltage should be measured using an oscilloscope; the noise after separation should be less than 50mVpp. Proper separation can improve the system's anti-interference capability by more than 30%.