Design of Reconfigurable Impedance Transformer and Its Application to Medium Voltage XLPE Power Cable with Joint in TV White Space

This paper presents the reconfigurable matching of 11 kV medium voltage (MV) cross-linked polyethylene (XLPE) underground cable with cable joint using a novel parallel coupled line (PCL) impedance transformer. For S-parameters characterization operated at TV white space (TVWS) based power line communication (PLC) spectrum ranged from 470 to 790 MHz, the proposed reconfigurable PCL impedance transformer with loaded and coupled lumped capacitors, namely Parallel Coupled Line with Loaded and Coupled Lumped Capacitors (PCL - LC2) is designed for the highest frequency impedance matching in TVWS. Integrating four capacitors gives the coupled line different coupling coefficients and achieves wide frequency tunability. From the experimental results of the 700-mm long cable section sample, reconfigurable modeling for 770 MHz with the 14 dB return loss of cable without a joint and the 15 dB return loss of cable with a joint is realized.