This paper introduces a new methodology for designing a robust Radio Frequency (RF) amplifier. In this method; the dimensions (area) and power (DC current bias) are scalable to match the RF design specifications. Many parameters are used to optimize the design results. The frequency scaling up nonlinearity is minimized with the trimming technique. The proposed method is firstly based on designing with low frequency corner specifications to avoid the parasitic effects, and then, the scaling process is starting. The ACM MOST is useful in analog CMOS circuit design. In this model, the current inversion coefficient is used as the design key. A set of simplest expressions allows quick design analytically as well as an evaluation of the design in terms of power consumption or silicon real state. The methodology has been implemented using MATLAB program and proved to be very practical and promising. A set of RF CMOS cascode amplifiers designs demonstrate the reliability of the proposed methodology.