Abstract: A method for designing the submillimeter wave sub-harmonically pumped mixer based on a hybrid circuit model is presented in this article. To resolve the difficulty of extracting the Schottky diode pairs model for submillimeter wave band mixer, a full wave electromagnetic analysis was implemented to extract the passive circuits parameters, and the DC <em<I-V</em< curve was used to characterize the diode cells nonlinear performance. The hybrid circuit model was established. On the basis of the hybrid model, a 2mm band subharmonical pumped mixer was designed and realized. The measured results show that its frequency conversion loss is less than 20dB from 116GHz to 120GHz. The measured conversion loss agrees well with the simulated one, which shows the validity of the proposed method as well as the hybrid circuit model.