How to ensure EMC for concentrators operating across different distribution zones?

When a concentrator communicates across different transformer substations (areas powered by different transformers), the signal must pass through the distribution transformer, resulting in significant low-frequency attenuation and the introduction of more noise. Ensuring EMC for cross-substation carrier communication requires signal enhancement and interference suppression. This involves increasing the carrier transmit power (within regulatory limits) and using high-efficiency coupling circuits (such as broadband coupling transformers). At the receiver, a high-performance bandpass filter with a center frequency equal to the carrier frequency and a bandwidth of ±5% is used to filter out out-of-band noise. The gain and linearity of the low-noise amplifier (LNA) at the receiver front end are enhanced. For power line filtering, a common-mode inductor CMZ1211-501T and a differential-mode inductor are used at the concentrator power input to prevent the carrier signal from being short-circuited by the power module. Simultaneously, all equipment must be properly grounded to reduce common-mode interference caused by ground potential differences. During cross-substation communication, a repeater can be used to boost the signal. The design allows for cross-substation communication distances exceeding 500 meters.