SimRF

Designing RF Subsystems

You can build RF receivers and transmitters by connecting blocks from the SimRF Circuit Envelope component libraries. The signals in these SimRF models are represented as voltages and currents. SimRF signals can be created externally in Simulink and passed into the SimRF models via the SimRF Inport, or signals can be created internally using SimRF sources. Each signal is associated with a carrier frequency that is determined by Inports, for Simulink generated signals, or by the native SimRF signal sources. The set of all carrier frequencies simulated in a SimRF model is defined in the SimRF Parameters block. Loading among blocks can be modeled using internal block impedances or explicitly using circuit elements.

Low-IF Hartley receiver (top) and simple direct conversion receiver (bottom) in SimRF. SimRF enables architectural design of RF subsystems by properly modeling the function, form, and interfaces of RF components.

Each of the nonlinear blocks in SimRF is characterized by IP3 and IP2. Noise associated with three blocks is specified by the noise figure parameter. A noise voltage source in SimRF can be used to inject additional noise into models where noise figure is not applicable or desired. You can author new components to include in your designs using the Simscape modeling language.

In addition to standard RF subsystems, SimRF also includes N-port S-parameter blocks. These blocks read standard Touchstone^® .snp files containing measured or simulated component data and enable the user to plot the data post import. Prior to simulation, SimRF applies a general rational function model to the measured S-parameters.