Design and realization of a submillimeter band sub-harmonic mixer based on the hybrid circuit model

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 I-V 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.