Guided Waves on Scalar and Tensorial Reactance Surfaces Modulated by Periodic Functions. A Circuital Approach

A technique to derive the propagation characteristics and field distributions of waves guided by scalar and tensorial reactance surfaces modulated by periodic or discrete Fourier spectrum functions in the propagation direction is presented. The method, based on an equivalent lumped circuits approach, can be seen as a generalization of the Oliner method for the TM propagation on scalar sinusoidally modulated reactance surfaces. Numerical results are obtained for both surface wave and leaky wave solutions. The relevance of these studies to modulated metasurface antennas is discussed.