System-level time-domain behavioral baseband modeling of RF blocks for mixed-signal simulation

This article presents a short survey of existing baseband (BB) signal flow models of linear and nonlinear RF blocks for system-level (SL) time domain (TD) transient simulation using Spice-like simulators. Existing BB models of nonlinear PB amplifier are analyzed and a corrected version of a publicly available model is proposed. A new nonlinear BB model of a mixer based on multiple Fourier series is proposed and tested as Verilog-A model. In comparison to the pass band (PB) mixer model the proposed BB model allows a speedup of transient simulation about 2-3 orders of magnitude and saves also time for verification of RF sub-systems implemented later in top-down design process on transistor level.