RF and Microwave Mixer Behavioural Modelling

Efficient models based on behavioural modelling techniques are needed for RF and microwave mixers in order to check the performances of communication systems. Here, we propose a model consisting on the cascade connection of an input equivalent filter, characterising the linear transmission and reflection memory effects, and an ideal nonlinear mixer model, providing the frequency translation and also the nonlinear amplitude and phase distortion for the central frequency. Model parameters can be obtained either from measurements or simulations of the mixer circuit. The reported models can be implemented in any commercial simulator by using standard library components and can be employed both in frequency and time-domain simulations, demonstrating good agreement and significant reduction of simulation time with respect to the simulation of detailed electrical circuit models. The modelling technique is illustrated through two WLAN IEEE 802.11a mixer examples: an up-converter and a down-converter. Key-Words: Behavioural Modelling, RF and Microwave Mixers, System Simulation, Linear Memory Effects, Nonlinear Memory-less Distortion.