Documentation Center

  • Trial Software
  • Product Updates

RF Toolbox Release Notes


New Features, Bug Fixes

General de-embedding function for 2N-port S-parameters

You can now use the deembedsparams function to de-embed 2N-port fixture effects from 2N-port measurements. It supports both three-dimensional S-parameters data and S-parameter objects.

N-port Touchstone file writing from any network data object or raw data

You can use the rfwrite function to write Touchstone files from three-dimensional network parameter data or any network parameter object (S-parameters, Y-parameters, Z-parameters, ABCD-parameters, etc.)

rationalfit function at least six times faster

The rationalfit function now fits a rational model to S-parameter data at least six times faster than previous releases. This responsiveness improves both RF Toolbox™ command-line behavior and SimRF™ simulation of S-parameter blocks.


New Features, Bug Fixes

Additional functions for constructing arbitrary RLC networks

In R2013b, the following new functions are available:

  • resistor, capacitor, inductor, and circuit — Use the basic building functions of an RF circuit to construct RLC networks.

  • add — Insert basic RF elements to a circuit.

  • clone — Duplicate any existing RF elements or circuits.

  • setports — Define node pairs as ports of a circuit.

  • setterminals — Map the nodes of a circuit to terminals.

S-parameter extraction for arbitrary RLC networks

The sparameters function now includes added functionality that you can use to calculate the S-parameters of RLC networks.


Bug Fixes, Compatibility Considerations

Improved rationalfit function

This release introduces additional pole-searching optimizations to the rationalfit function algorithm. Models that the function returns in this release tend to have fewer poles than those in previous releases.

Compatibility Considerations

To constrain the function results across releases and machine architectures, explicitly specify optional parameters such as error tolerance and number of poles when you call the function. Given a data set and corresponding frequencies, the function attempts to calculate a rational function approximation to within a given specification. However, the exact model that the function returns can differ between releases and machines, as the algorithm improves.


New Features, Bug Fixes

Network parameter interface improvements for faster reading of Touchstone files, plotting, and converting parameters

New network parameter objects and functions are available, with support for:

  • Reading Touchstone files

  • Converting network parameters

  • Plotting network parameters

Additionally, some functions have been updated to support the new interface. For more information, see RF Network Parameter Objects.

Name-value pair syntax for rationalfit function

The rationalfit function now supports using name-value pairs for optional input arguments. Name-value pair arguments can be specified in any order and improve readability of code.


New Features, Bug Fixes

New Visualization Option for Intermediate-Frequency (IF) Planning Object

The OpenIF object supports a new interactive, graphical interface for assessing spur information in a mixer chain. You access this interface using the new show method.

Enhanced S-Parameter Conversion Functions

S-parameter conversion functions have been enhanced to support larger data sets. The following functions now support conversion between parameter sets of 2N-port networks.

The s2smm function now supports mixed-mode conversions for N-port devices.

The following mixed-mode S-parameter functions now support mixed-mode conversions for 2N-port devices:

New Demos for Signal Integrity Applications

Two new signal-integrity demos are available in this version.

Enhanced Rational Fitting

The rationalfit function has improved robustness, speed, and accuracy in this version.


New Features, Bug Fixes, Compatibility Considerations

New Intermediate Frequency (IF) Planning Object

The OpenIF object supports a new partial workflow for multiband transmitter or receiver design. Use these objects to analyze intermediate frequencies (IFs) that do not produce interference (spurs) in operating bands.

New Functions for Calculating Transmission Line RLGC Parameters

The rlgc2s and s2rlgc functions allow you to calculate the per-unit-length RLGC parameters of a transmission line from transmission-line S-parameters.

Enhanced Rational Fitting

The rationalfit function has improved robustness, speed, and accuracy in this version.

Compatibility Considerations

Some default values of rationalfit have changed. For more information, see the function reference page.

Conversion of Error and Warning Message Identifiers

For R2011b, error and warning messages identifiers have changed in RF Toolbox software.

Compatibility Considerations

If you have scripts or functions that use message identifiers that changed, you must update the code to use the new identifiers. Typically, message identifiers are used to turn off specific warning messages, or in code that uses a try/catch statement and performs an action based on a specific error identifier.

For example, the rf:rfckt:seriesrlc:setpositive:NotAPositive identifier has changed to rf:rfbase:rfbase:setpositive:NotAPositive. If your code checks for rf:rfckt:seriesrlc:setpositive:NotAPositive, you must update it to check for rf:rfbase:rfbase:setpositive:NotAPositive instead.

To determine the identifier for a warning, run the following command just after you see the warning:

[MSG,MSGID] = lastwarn;

This command saves the message identifier to the variable MSGID.

To determine the identifier for an error, run the following command just after you see the error:

exception = MException.last;
MSGID = exception.identifier;

    Note:   Warning messages indicate a potential issue with your code. While you can turn off a warning, a suggested alternative is to change your code so it runs warning-free.


Bug Fixes


New Features, Compatibility Considerations

Enhanced Rational Function Modeling

An improved algorithm for the rationalfit function fits an accurate rational model to passive S-parameter data in less time than in previous versions. In addition, a new parameter specifies the number of iterations rationalfit attempts at each value for the number of poles.

Compatibility Considerations

Default behavior for some parameters have changed:

  • The number-of-poles argument npoles defaults to a minimum value of 0 in version 2.8, instead of 4, as in previous versions.

  • rationalfit does not display a wait bar by default in this version. A new showwaitbar parameter allows you to specify whether rationalfit displays a wait bar.

For more information on using this function, see the rationalfit reference page.

Extended Methods and Parameters for RF Object Visualization

RF Toolbox version 2.8 extends the Plots and Charts methods to include:

  • Support for third-order intercept point and transducer power gain parameters, IIP3 and Gt.

  • A new method, table, for visualizing network data in the Variable Editor.


New Features

Function Added

The makepassive function creates passive S-Parameters from any S-parameter array. Use this function to enforce strict numerical passivity on an array of S-parameters that represents a passive device.

Methods Added

Two new methods for rfmodel.rational objects are available:

  • The ispassive method tests global passivity of an rfmodel.rational object.

  • The stepresp method calculates the response of an rfmodel.rational object to a step signal. You can use this function to perform time-domain reflectometry (TDR) and time-domain transmission (TDT) analysis.

Demo Added

The Modeling a High-Speed Backplane (Part 3: 4-Port S-Parameters to Differential TDR and TDT)Modeling a High-Speed Backplane (Part 3: 4-Port S-Parameters to Differential TDR and TDT) demo shows how to perform time-domain reflectometry (TDR) and time-domain transmission (TDT) analysis on network data.


New Features, Bug Fixes

New Function for Testing Passivity of S-Parameters

The ispassive function checks the passivity of N-port S-parameter matrices.

Expanded Port-Ordering Schemes for S-Parameter Conversion Functions

The functions s2scc, s2scd, s2sdc, s2sdd, s2smm, smm2s now support a third commonly-used port-ordering. For more information on using this feature, see the corresponding function reference page.

Support for Calculation of Power-Wave Gain for Transfer Functions

The s2tf function can now calculate the power-wave gain of 2-port S-parameters. Calculation in terms of voltage is still the default option.


New Features, Compatibility Considerations

New Functions for Converting 4N-Port S-Parameter Matrices

There are two new functions for converting between 4N-port single-ended S-parameter matrices and 2N-port mixed-mode S-parameter matrices:

  • The s2smm function lets you convert 4N-port single-ended S-parameters to 2N-port mixed-mode S-parameters. You can view the 2N-port output data to see interactions, such as crosstalk, that are not apparent in the single-ended data. This lets you easily select the ports of interest for further analysis.

  • The smm2s function lets you convert 2N-port mixed-mode S-parameters to 4N-port single-ended S-parameters.

Enhanced Dielectric Loss Model in Three Transmission Line Objects

The following objects now provide a more realistic model for dielectric loss:

To specify dielectric loss, you use a new property, LossTangent. This property replaces the SigmaDiel parameter.

Compatibility Considerations

Your existing objects with a nonzero value for the SigmaDiel parameter no longer model dielectric loss. Instead, the objects issue a warning message and use the default value of zero for the LossTangent property when you use the analyze method.

Demos Added

Two new demos show how to design broadband impedance matching networks for RF components:


New Features

cascadesparams Function now supports N-port S-parameters

You can now use the cascadesparams function to cascade the S-parameters of an arbitrary number of N-port devices to form a network. The function lets you specify how to connect the ports of each N-port device to the ports of the subsequent N-port device in the cascade. For more information about the function, see the cascadesparams reference page.

Improvements to the plotyy Method

The plotyy method now uses a more intuitive approach when determining how to plot the specified parameters if you do not specify the plot format. For more information about the function, see the plotyy reference page.


New Features

Calculation and Plotting Metrics Added

You can now compute and visualize group delay, voltage gain, and stability factor using the calculate and plot methods.

Network Parameter Conversion Functions Enhanced

You can now use the s2sdd, s2sdc, s2scd, and s2scc functions to perform conversions on network parameters with alternate port arrangements.

gammams and gammaml Functions Added

Use the new gammams and gammaml functions to compute source and load reflection coefficients required for simultaneous conjugate match.

z2gamma Function Added

Use the new z2gamma function to convert impedance values to reflection coefficients.

Demos Added and Updated

A new demo, Writing a Touchstone FileWriting a Touchstone File, shows how to write rfckt object data to an industry-standard Touchstone data file.

Command-Line Help Updated

The help function returns additional information for objects and packages. The function now includes descriptions of all properties and links to all relevant methods.


New Features

snp2smp Function Added

Use the new snp2smp function to convert N-port S-parameter data and termination impedances to M-port S-parameters.

circle Method Added

Use the new circle method to place circles on a Smith® Chart to depict stability regions and display constant gain, noise figure, reflection, and immitance circles.

powergain Function Added

Use the new powergain function to compute various power gains of a 2-port network.

Smith Chart Enhanced

The smith method now lets you plot the network parameters of devices with more than two ports on a Smith Chart.

Demos Added and Updated

Modeling a High-Speed Backplane (Part 1: Measured 16-Port S-Parameters to 4-Port S-Parameters)Modeling a High-Speed Backplane (Part 1: Measured 16-Port S-Parameters to 4-Port S-Parameters) is the new first part of a four-part demo on "Modeling a High-Speed Backplane." The new demo shows how to extract 4-port S-parameter data from 16-port S-parameter data. The original three parts of the demo are now parts 2, 3, and 4.

The following demos replace the "Designing Impedance Matching Networks" and "Placing Circles on a Smith Chart" demos, respectively, and show how to use the new circle method:


New Features

Agilent P2D and S2D System-Level Verification Model Support Added

The rfckt.amplifier and rfckt.mixer objects now let you import system-level verification models of amplifiers and mixers, respectively, using data from Agilent® P2D and S2D files.

Use P2D files to specify the following data for multiple operating conditions, such as temperature and bias values:

  • Small-signal network parameters

  • Power-dependent network parameters

  • Noise data

  • Intermodulation tables

Use S2D files to specify the following data for multiple operating conditions:

  • Small-signal network parameters

  • Gain compression (1 dB)

  • Third-order intercept point (IP3)

  • Power-dependent S21 parameters

  • Noise data

  • Intermodulation tables

Use the following methods to work with operating condition data after you import a P2D or S2D file into an RF object:

  • setop — Use this method to set operating condition values or to list all available values.

  • getop — Use this method to display the selected operating condition values.

Mixer Spur Analysis Added

You can import an intermodulation table into an rfckt.mixer object. The object's plot method has a new option for plotting mixer spur data.

timeresp Method Added

Use the new timeresp method of the rfmodel.rational object to compute the time response of an rfmodel object to a specified input signal. Use this method rather than computing impulse response with the impulse method and then convolving that response with the input signal because the timeresp method generally gives a more accurate output signal for a given input signal.

Plotting Methods Added

Four new plotting methods provide additional plotting options:

  • Use the plotyy method of the rfckt class to create a plot that contains RF circuit object data on both the left and right Y-axes.

  • Use the loglog method of the rfckt class to plot RF circuit object data on a log-log scale.

  • Use the semilogx method of the rfckt class to plot RF circuit object data using a logarithmic scale for the X-axis.

  • Use the semilogy method of the rfckt class to plot RF circuit object data using a logarithmic scale for the Y-axis.

gamma2z Function Added

Use the new gamma2z function to compute input impedance from a reflection coefficient.

Tab Completion Added

Tab completion is now available in the MATLAB® command window for all functions and methods. For more information on tab completion, see the MATLAB documentation.

Data Tips Added

Data tips are now available for any RF plot. For more information on data tips, see Data Cursor — Displaying Data Values Interactively in the MATLAB documentation.

Demos Added and Updated

Visualizing Mixer SpursVisualizing Mixer Spurs shows how to use the toolbox to perform mixer spur analysis using data from an intermodulation table and then plot the output power spectrum of the desired signal and the undesired spurs.


New Features

S-Parameter Conversion Function Added

Use the s2tf function to convert 2-port scattering parameters into a transfer function that represents the normalized voltage gain of a 2-port network.

rfmodel Class Added

Use objects from the rfmodel class to represent components and networks with mathematical equations. The rfmodel.rational object stores a rational function model of a component or network.

rationalfit Function Added

Use the rationalfit function to fit a rational function to passive data that represents an RF component or network and then store the result in an rfmodel.rational object. This type of model is useful to signal integrity engineers, whose goal is to reliably connect high-speed semiconductor devices with, for example, multi-Gbit/s serial data streams across backplanes and printed circuit boards.

freqresp and impulse Functions Added

Use the freqresp method of the rfmodel class to compute the frequency response of an rfmodel object.

Use the impulse method of the rfmodel class to compute the impulse response of an rfmodel object.

Support for Exporting Verilog-A Models Added

Use the writeva method of the rfmodel class to export a description of an RF component or network for use in a time-domain circuit simulator.

Demos Added

"Modeling a High-Speed Backplane (Part 1: Measured 4-Port S-Parameters to a Rational Function Model)" shows how to use the toolbox to model a differential high-speed backplane using rational functions.

"Modeling a High-Speed Backplane (Part 2: Rational Function Model to a Verilog-A Module)" shows how to use toolbox functions to generate a Verilog-A module that models the high-level behavior of a high-speed backplane.

"Modeling a Differential High-Speed Backplane in Simulink" shows how to use Simulink to simulate a differential high-speed backplane.


New Features

S-Parameter Conversion Functions Added

Use the s2scc function to convert 4-port, single-ended S-parameters to 2-port, common mode S-parameters.

Use the s2scd function to convert 4-port, single-ended S-parameters to 2-port, cross mode S-parameters.

Use the s2sdc function to convert 4-port, single-ended S-parameters to 2-port, cross mode S-parameters.

Use the s2sdd function to convert 4-port, single-ended S-parameters to 2-port, differential mode S-parameters.


New Features

extract Function Added

Use the extract function to extract specified network parameters from a circuit or data object and return the result in an array.

Circuit Object Added

Use rfckt.rlcgline to construct an RLCG transmission line object.

Transmission Line Object Improved

The new Freq property of the circuit object, rfckt.txline, is a vector of positive frequencies at which the parameter values are known.

The Loss, PV, and ZO properties of the circuit object, rfckt.txline, can now be vectors of line loss, phase velocity, and characteristic impedance values that correspond to the frequencies specified in the Freq property.

The new IntpType property of the circuit object, rfckt.txline, is the interpolation method used to calculate the parameter values between the known frequencies.

Touchstone Data File Support Improved

You can now read data from Touchstone data files that contain comments and spaces between sections of data.

Demos Improved

The demos have new documentation and can be accessed using an improved interface.

Command Window Help for Functions That Act on Circuit Objects Added

You can access help for functions that act on circuit objects by using the syntax help functionname at the MATLAB command prompt.


New Features

Plot Figures Integrated into the RF Tool GUI

In earlier versions, a plot figure would appear in a separate window after clicking the Plot button. In this version, plot figures are integrated into the GUI itself.

Five Objects Added

These objects can be used to store rfdata such as network parameters, noise figure, power, IP3, and spot noise.

Three Circuit Objects Added

Use rfckt.delay to model delay lines, rfckt.hybridg to model hybrid G connected networks, and rfckt.passive to model RF passive networks.

Methods Added

The new write method allows saving of RF network data into files for all rfckt objects.

The new methods, read and restore, read and restore data for rfckt.datafile, rfckt.amplifier, and rfckt.mixer.

Method Enhanced

The analyze method now takes three additional optional inputs for the load, source, and reference impedances.

Functions Added

The functions stabilitymu and stabilityk calculate the stability factors µ and k.

The functions h2g and g2h convert between hybrid G and hybrid H parameters.

General Enhancements

It is now possible to create the objects rfckt.amplifier and rfckt.mixer from a MATLAB variable.

The frequency-dependent NF and IP3 data types were added to the AMP format.

Compatibility Summary

ReleaseFeatures or Changes with Compatibility Considerations
R2013aImproved rationalfit function
R2010bEnhanced Rational Function Modeling
R2009aEnhanced Dielectric Loss Model in Three Transmission Line Objects
Was this topic helpful?