Coupler with transformer for impedance matching on mv power distribution line for BPLC

In this paper, the couplers with transformers for the purpose of impedance matching at signal input terminal of Medium Voltage(MV) power distribution lines for Broadband Power Line Communication(BPLC) which used in the frequency range of 1 MHz to 35 MHz have been designed, and the performance of those has been verified experimentally. In fact, the input impedance values of MV power distribution lines have been obtained between 200Omega and 300Omega[6]. In the range of these values, we have designed the transformers with general specific values of impedance: 50Omega, 112Omega, 253Omega, 356Omega, and 450Omega by utilizing the Ruthroffs transmission line transformer method[7]. The most proper transformer, matching well is embedded in a coupler and is implemented to transfer a transmitting signal with maximum power into the MV distribution lines. The performance of the designed coupler with a transformer is verified through measuring the reflection characteristics and signal attenuation in given MV test field. The measured results have informed that the couplers with transformers with impedance values of 253Omega or 356Omega have represented the best performance of them.