Bloch impedance
= Bloch impedance
{c}
{title2=$Z_B=V/I$}
The voltage-to-current ratio of a selected Bloch eigenmode at a specified position within a periodic cell. It depends on the chosen cell boundary, unlike the cell's propagation <eigenvalues>. In a pass band a physical semi-infinite mode carries positive real power; in an ideal stop band its <input impedance> is reactive and the mode decays into the line.