A theoretical study of rough electrodes is succinctly presented, for small-size and smooth-shape roughness situations. The analytical result is a formula which describes the resulting impedance in terms of the parameters of the shape of such a roughness. An equivalent electrical network is then derived with very simple formulae in order to calculate the component values. The most original part of the results consists in specific theoretical examples. Several times, impedances with the term (iomega)v with a non integer exponent (nu) are obtained. This paper shows that from a theoretical point of view, smooth roughness profiles with some simple shapes may result in a special type of impedance known as Constant Phase Angle (CPA). In some specific cases, impedances with the term log(iomega) are also obtained.