This paper describes a generalized analytical-numerical model of “Smart” RF equalizer, for ultra-wideband power amplifiers (PA) applications. The novelty of this study consists of generating a universal gain-equalizer database, set from electromagnetic (EM) software, and processed with analytical tools, to deal with any random PA gain profile in real time. A numerical tool is then developed to compute lumped elements values , from a random gain response imported in S2P file format , to achieve given specifications in terms of gain flatness and frequency band. These values are finally injected in a 3D EM realistic simulation to ensure a final accurate validation of the Equalizer. A concrete example of a microstrip equalizer is illustrated in the frequency band [1 GHz to 6 GHz] and experimental results are depicted to validate the proposed method.