Parametric representation of wave propagation in nonuniform media (both   in transmission and stop bands)
  An analytical approach based on the parametric representation of the wave propagation in nonuniform media was considered. In addition to the previously developed theory of parametric antiresonance describing the field attenuation in stop bands, in the present paper the behaviour of the Bloch wave in a transmission band was investigated. A wide class of exact solutions was found and the correspondence to the quasi-periodic Floquet solutions was shown. 
A. Popov and V. Kovalchuk
math-ph math.MP