Plasma surface presented as array of virtual ports

Calculations aimed at representing the plasma-vacuum boundary condition in real space are presented. Some ideas about how this representation can be used for power coupling analysis and antenna modeling are put forward. The relation between tangential electric and magnetic fields on the plasma surface is linear and customary expressed in the spectral domain for every partial wave via 2×2 plasma impedance matrix - Z^p(k_y,K_z). In this work, the tangential fields E^⇀_t and B ^→_t on the plasma surface are projected on a suitably chosen set of basis functions. Then the linear operator relating the components E^⇀_t and B^→_t expressed in such a way is derived from the known matrix Z^p(k_y,K _z). It is shown that in this representation the plasma surface has properties similar to the array of ports of a microwave system and can be formally described by a corresponding impedance matrix in the way it is done in microwave analysis. The obtained representation can be exploited for deeper understanding of the RF power coupling to the plasmas, antenna modeling, measurements of plasma electromagnetic properties and for plasma modeling with suitably designed structures or metamaterials.