A compact scalable large signal model for GaAs Schottky diodes including edge effect and dc/ac dispersion is proposed in this article. The scalable rules for extrinsic resistance and intrinsic model parameters are given in detail. The experimental and theoretical results show that at the same bias condition, good scaling model parameters can be achieved between the diodes with different anode equivalent junction areas. Good scaling of the large signal model parameters can be achieved between the large-size devices and elementary cell. Model verification is carried out by the comparison of measured and simulated dc and S-parameters for two diodes with different sizes in parallel up to 170 GHz.