Design of a T-coupling circuit for PLC on broadband

Couplers have an important role for Power Line Communications (PLC). They allow plugging communication equipment to the power line to use it as a medium for communication and to filter out the low-frequency power signal. This is a challenging problem since PLC intends to use the power line as a broadband communication channel. Couplers should also meet other requirements since they are the link to the power network. In this paper, the design, simulation and implementation of a broadband coupling circuit with a T configuration is described. The circuit is a low cost implementation since it uses just a few components. The bandwidth proposed is the lower band of the IEEE 1901 Standard (1.8 – 30MHz) [1]. The design development is done considering the impedance of the power line. To get better accuracy in the behavior of the coupler, simulations are made to evaluate its performance in the frequency domain. The design is validated using an experimental setup and the measuring its S-parameters. In both cases several loads are used. Finally, this work describes the results and reviews the circuit performance.