A simple model for a dielectric layer leaky-wave antenna is proposed; it represents the antenna as a leaky parallel-plate waveguide that consists of a grounded substrate layer with a shunt admittance screen on top. This simple model is then analyzed using a transverse equivalent network model in which the shunt admittance screen is modeled as a shunt load admittance in an equivalent circuit description. This equivalence allows for simple computer-aided design formulas to be obtained for all of the radiation properties of the dielectric layer leaky-wave antenna structure. Although derived in detail for a two-layer structure, the method can also be used for structures with multiple dielectric layers, which have been described in the literature as one-dimensional electromagnetic bandgap (EBG) structures.