Complex path impedance estimation and matching requirements for body-coupled communication

Capacitive body coupled communication (BCC) channel has been modeled as a two-port complex path impedance matrix [Z] which varies as a function of ten different body positions over the frequency range of 1 MHz to 60 MHz. A systematic numerical simulation methodology has been used to estimate [Z] parameters. The estimated complex path impedance [Z] is a symmetric matrix showing BCC channel is a reciprocal network of passive components for given coupler configuration, body positions and frequency range. The estimated complex path impedance has been utilized to determine either input impedance Z_in or output impedance Z_out to conjugately match to Z_s at transmitter or Zl at receiver, respectively for maximum power transfer. It has been found that the resistive matching below 1000 Ω and inductive matching between 0.5 μH to 5 μH on any side of the two ports can meet the conjugate matching requirements for maximum power transfer for the given body positions and frequency range.