Design parameter space for width-modulated microstrip line based periodic unit cell

Parametric analysis and solutions for controlling the surface waves phase velocity in planar periodic structures are presented. Here a geometry obtained by 2D repetition of a unit cell consisting of a width-modulated microstrip line is considered. The electromagnetic response expressed in terms of dispersion diagram is essential for the design of devices exploiting properties of the structure. In this context, various parameters of the unit cell such as cell dimensions, amplitude of the modulation and average value of the effective dielectric constant have been considered allowing a full control of the frequency response for different configurations.