How to select a bandpass filter for a power line carrier PLC?

The selection of a power line carrier bandpass filter for a PLC requires consideration of parameters such as center frequency, bandwidth, insertion loss, and out-of-band rejection. First, determine the carrier center frequency f0, for example, 132kHz. The bandwidth BW should be determined according to the communication protocol requirements, such as 10kHz. Select an LC resonant circuit, using a high-Q wire-wound inductor such as CMZ2012A-900T (90μH), and an NPO ceramic capacitor, calculated using the formula C=1/(4π²f0²L). The filter topology can be Butterworth or Chebyshev type, selected based on requirements for in-band flatness and out-of-band attenuation. In actual selection, use a network analyzer to test the filter's S-parameters, ensuring that the in-band insertion loss is less than 1dB and the out-of-band attenuation is greater than 30dB at f0±50kHz. Considering temperature stability, select capacitors with a temperature coefficient of ±30ppm/℃ and low-temperature-coefficient magnetic cores. Through optimization, ensure that the filter's frequency drift is less than 1% within the range of -40℃ to 85℃, guaranteeing communication stability.