SimRF™ extends Simulink® with blocks for designing RF systems and simulating their performance, taking into account the effects of impedance mismatches, wideband spectral regrowth, and interfering and blocking signals.
SimRF enables you to model and rapidly simulate RF transmitters and receivers for wireless applications such as radar or communication systems.
You can use SimRF to build system-level executable specifications and perform what-if analyses with different RF front-end architectures, or you can commit to a particular architecture and use simulation to develop digital signal processing algorithms to mitigate RF impairments. With SimRF, you can refine the executable specifications of the RF subsystem while improving communication between system architects and RF or analog engineers.
By integrating SimRF models with communications algorithms you can model digitally-assisted systems such as RF receivers with adaptive automatic gain control (AGC) and RF transmitters with digital pre-distortion (DPD) architectures based on feedback loops.
You can improve the accuracy of your model following a bottom-up approach by importing measurement data such as Touchstone files and AM/AM AM/PM data. You can use S-parameters in SimRF models and estimate frequency-dependent impedance mismatches between linear and nonlinear components in the time and frequency domains.
The set of RF impairments you can model in SimRF includes:
You can build RF receivers and transmitters by connecting blocks from the SimRF component library, or you can automatically generate a SimRF model using the RF Budget Analyzer app. With the RF Budget Analyzer app you can graphically build and analyze a cascade of RF components and automatically generate a SimRF model and test bench for circuit envelope simulation.
The RF Budget Analyzer app lets you rapidly start modeling RF transmitters and receivers for wireless applications and validate simulation results in different operating conditions by comparing them with analytical predictions. You can use this app to determine the system-level specs of your RF transceiver instead of relying on custom spreadsheets and complex computations.
You can use the automatically generated model as a baseline for further elaboration of the RF architecture and for simulation effects of imperfections that cannot be accounted for analytically, such as leakage and interferers.
SimRF provides two modeling libraries for describing RF systems at different abstraction levels. Digital signal processing engineers can use the Equivalent Baseband library to estimate the impact of RF phenomena on overall system performance. RF designers can use the Circuit Envelope library to refine transceiver architectures with increased modeling fidelity.
At a higher level of abstraction, you can model a chain of RF components using blocks from the Equivalent Baseband library. You can perform budget analysis and simulations of your system, including RF impairments such as noise and odd-order nonlinearity. When you use blocks from the Equivalent Baseband library, the simulation is performed using a baseband equivalent model of the RF chain. This enables single-carrier simulation of super heterodyne transceivers, taking into account in-band spectral regrowth, noise, and impedance mismatches among blocks.
At a lower level of abstraction, blocks from the Circuit Envelope library let you model arbitrary topologies, examine alternative architectures for your RF system, and track the effects of RF impairments through the model. When you use blocks from the Circuit Envelope library, signals in the SimRF models are represented as voltages and currents. As a result, impedance mismatch, reflection, and finite isolation are correctly taken into account.
SimRF provides models of amplifiers, mixers, impedances, transmission lines, filters, and other RF components. For amplifiers and mixers, you can specify linear and nonlinear properties such as component gain, noise figure, second- and third-order intercept points (IP2 and IP3), 1dB compression point, and saturation power. With components such as power combiners, splitters, circulators, switches, and transformers you can build arbitrary RF networks based on data sheet parameters and define the system specifications following a top-down approach. Frequency dependent components enable you to evaluate the effects of impedance mismatch, reflection, finite, isolation, and leakage.
You can describe components using S-parameters and AM/AM AM/PM data. By specifying the input/output impedance of linear and non-linear components you can estimate the effect of frequency-dependent impedance mismatches on noise and power transfer.
You can author your own RF models using the Simscape language and build custom RF components. For example, you can model power amplifiers using the Simscape language to define custom equations based on modified Volterra series. With Simscape you can model low-frequency analog electronics chains and simulate them with SimRF.