Conventional solid-state power amplifier (SSPA) design approach isolates RF design from communication theory. In this paper, a unified SSPA design approach is proposed which optimizes SSPA parameters (bias voltage and input RF signal power) to minimize total DC power consumption while satisfying received SNR constraint specified by the link budget. The effect of SSPA nonlinearity is quantified by the error vector magnitude measured at its output and the corresponding received SNR degradation is analyzed. Using the quantitative metrics for received SNR, it is possible to evaluate highly nonlinear SSPA classes such as Class-B or deep-Class AB which are normally not considered in conventional SSPA design approach to be used in satellite communication applications.