Classifying Typical Residential Rooms for Narrow-Band Impedance Adaptation

Little work has been done on the topic of power-line impedance adaptation, especially for low-voltage networks. Further, the variations in network topology combined with unknown cable and load impedances, obscure the requirements for impedance adaptation, causing researchers and manufacturers to default to a guessed impedance level and a fixed winding ratio. Attempting to clarify said requirements, this paper utilizes a simple model to linguistically describe narrowband power-line conditions. Simulation results are experimentally verified for 50-Omega modems at frequencies below 1 MHz. Next, typical residential rooms are classified in order to propose proper coupler winding ratios for impedance adaptation. Live 220-V measurements indicate that results are useful regardless of power-line topology, yielding gains up to 10 dB.