Circuit Envelope Library

Use Circuit Envelope Library

The RF Blockset™ Circuit Envelope library provides components to model RF systems within the Simulink^® environment. This library extends your Simulink modeling environment with a library of blocks, including Amplifier, Mixer, Filter, and Antenna, to model RF systems. Use blocks from the Circuit Envelope library to model electrical components by specifying RF properties or by importing measured data.

The RF Blockset Circuit Envelope library enables simulation of arbitrary and cascaded RF networks with multicarrier frequencies, noise, and nonlinearities. The Elements, Junctions, Sources, Systems, Testbenches, and Utilities sublibraries enable you to model noise, nonlinear elements, and RF architecture. You can import S-parameter data files directly into RF Blockset models to specify linear networks, and you can visualize their frequency response using the S-Parameters block. Use the Testbenches sublibrary to measure and verify gain, noise figure, and intercept point. Additionally, using this library you can also author custom blocks using Simscape™ language.

Open Circuit Envelope Library

To open the main library window, type this at the MATLAB^® Command Line:

rflib

Each yellow block in the window represents a library.

Double-click the Circuit Envelope block to open the library.

This table describes the sublibraries and the available models.

Sublibrary	Use
Elements	To model antenna, amplifier, filter, mixers, and other RF elements.
Junctions and Switches	To model ideal frequency-independent circulators, couplers, and dividers and to use switches and potentiometers.
Systems	To model a modulator/demodulator and an IQ modulator/demodulator.
Testbenches	To measure and verify gain, noise figure, intercept point, and S-parameters.
Sources	To use current or voltage in noise, sinusoidal, and continuous wave sources and power in sinusoidal and continuous wave sources.
Utilities	To define system simulation settings, convert input signal to RF Blockset signal, convert RF Blockset signal to Simulink output signal, and connect ports.

Understanding Circuit Envelope Environment

The Circuit Envelope environment comprises of groups of interconnected Circuit Envelope library blocks and algorithms that model an RF system. In the Circuit Envelope environment, all blocks fall into one of the three following categories.

Blocks Operating Within Circuit Envelope Environment

These blocks contribute to the physical representation of an RF system. Most Circuit Envelope library blocks fall into this category, including all blocks in the Elements and Sources sublibraries. For example, a Resistor block can model a source impedance or part of a matching network, and an Amplifier block can model a physical RF amplifier. Both of these blocks model physical components.

Blocks with variable properties, such as a Variable Resistor or a VGA block, operate within the Circuit Envelope environment, although the control signals come directly from Simulink and you do not require to use cross-domain blocks.

Blocks Operating Between Circuit Envelope and Simulink Environments

These blocks, also called cross-domain blocks, provide an interface from an RF system to a larger design. The Inport and Outport blocks from the Circuit Envelope library fall in this category. For example, you can construct a signal using blocks from Communications Toolbox™ or DSP System Toolbox™ libraries, and you can input that signal into the RF Blockset environment using an RF Blockset Inport block.

Environment Independent Block

The Configuration block manipulates the environment and determines the simulation configuration. To use this block, connect it to any part of the RF system. Because the block is not a part of the physical representation of the system, it has the same effect regardless of where you connect it.

To run models containing other Circuit Envelope blocks, you must connect a Configuration block to the network.

Related Topics

• Circuit Envelope Basics