  We propose a surface-wave dispersion retrieval method and synthesis technique
that applies to bianisotropic metasurfaces that are embedded in symmetric or
asymmetric environments. Specifically, we use general zero-thickness sheet
transition conditions to relate the propagation constants of surface-wave modes
to the bianisotropic susceptibility components of the metasurface, which can
themselves be directly related to its scattering parameters. It is then
possible to either obtain the metasurface dispersion diagram from its known
susceptibilities or, alternatively, compute the susceptibilities required to
achieve a desired surface-wave propagation. The validity of the method is
demonstrated by comparing its results to those obtained with exact dispersion
relations of well known structures such as the propagation of surface plasmons
on thin metallic films. In particular, this work reveals that it is possible to
achieve surface-wave propagation only on one side of the metasurface either by
superposition of symmetric and asymmetric modes in the case of anisotropic
metasurfaces or by completely forbidding the existence of the surface wave on
one side of the structure using bianisotropic metasurfaces.
