How to match the carrier wave in a common-mode inductor of a power line carrier PLC?

The selection of common-mode inductors for power line carrier PLCs needs to be based on a comprehensive consideration of the carrier frequency, impedance characteristics, and current capacity. First, determine the carrier operating frequency band, for example, within the 100-500kHz range. Select a common-mode inductor with an inductance value of 50-200μH, such as CML4532A-510T (51μH) or CML3225A-101T (100μH). Use an impedance analyzer to measure the inductor's actual impedance at the carrier frequency, ensuring that the impedance is greater than 100Ω in the target frequency band. Simultaneously consider saturation current, selecting products with sufficient core cross-sectional area to prevent magnetic saturation under high current, which could lead to a decrease in inductance. For high-frequency carriers, use low-loss ferrite materials such as PC44 to reduce core losses. During layout, the common-mode inductor should be placed close to the power line input, with leads as short as possible to minimize the impact of parasitic parameters. Through practical testing, the common-mode rejection ratio (CMRR) should be greater than 20dB in the carrier frequency band to ensure effective suppression of common-mode noise without affecting signal transmission.