This paper presents the study of a method used for decoupling radiating elements in the case of a multiband structure dedicated to small LTE Smart Cells. This method consists in using a power splitter and a phase shifter connected between the feeds of the two groups of radiating elements. The study begins with a monoband structure made up of printed monopoles and a wired standing one. The impact on the validity of the method, due to the introduction of two additional bands through the addition of parasitic elements was then studied. A prototype was realized and tested and he measurements are discussed in this paper.