Backscattering in Twisted-Pair Nonhomogeneous Transmission Lines

Research output: Contribution to journalArticle


The development of the communication networks tends gradually toward exploiting higher frequencies, sometimes even reaching the lowest microwave band (P-band). As the signal bandwidth used for transmission over twisted-pairs increases, as recommended by and other broadband systems, new phenomenon was observed, namely, backscattering. Motivated by the measurements of copper cables in frequency band up to 400 MHz, we propose a novel backscattering model. It may be productively applied to the problem of loop diagnostics. The methods to accurately and reliable determine the relevant transmission-line parameters are sine qua non condition to appropriately exploit the potential of short-to-medium range access lines. In this paper, a recursive formulation of the frequency-domain response of the backscattering is used for a space-time characterization. To confirm the practical use of the finding, we evaluate the properties of a loop using wideband, high-frequency S₁₁ measurements of the real cables. These laboratory results confirm the effectiveness and accuracy of the proposed method.


External organisations
  • Ericsson AB
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Communication Systems


  • Backscatter, Backscattering, Bandwidth, electromagnetic modeling, Frequency measurement, Impedance, instrumentation and measurement techniques, nonuniform transmission lines, Power cables, propagation in complex media, Signal resolution, single-ended line test (SELT), time-domain reflectometry (TDR), Topology, transmission-line theory
Original languageEnglish
Pages (from-to)2674-2682
JournalIEEE Transactions on Microwave Theory and Techniques
Issue number6
Early online date2018 Apr 10
Publication statusPublished - 2018
Publication categoryResearch