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.
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.)
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.
In R2013b, the following new functions are available:
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.
The sparameters function now includes added functionality that you can use to calculate the S-parameters of RLC networks.
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.
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 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.
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.
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:
Two new signal-integrity demos are available in this version.
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.
Some default values of rationalfit have changed. For more information, see the function reference page.
For R2011b, error and warning messages identifiers have changed in RF Toolbox software.
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;
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.
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.
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.
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.
Two new methods for rfmodel.rational objects are available:
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.
The ispassive function checks the passivity of N-port S-parameter matrices.
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.
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.
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.
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.
Two new demos show how to design broadband impedance matching networks for RF components:
Designing Broadband Matching Networks (Part 1: Antenna)Designing Broadband Matching Networks (Part 1: Antenna) shows how to design a matching network for an antenna.
Designing Broadband Matching Networks (Part 2: Amplifier)Designing Broadband Matching Networks (Part 2: Amplifier) shows how to design a matching network for an amplifier.
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.
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.
Use the new z2gamma function to convert impedance values to reflection coefficients.
Modeling a High-Speed Backplane (Part 2: 4-Port S-Parameters to a Rational Function Model)Modeling a High-Speed Backplane (Part 2: 4-Port S-Parameters to a Rational Function Model) now uses the new Communications Toolbox™ eye diagram scope, commscope.eyediagram, to plot the eye diagram.
Use the new snp2smp function to convert N-port S-parameter data and termination impedances to M-port S-parameters.
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.
Use the new powergain function to compute various power gains of a 2-port network.
The smith method now lets you plot the network parameters of devices with more than two ports on a Smith Chart.
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:
Designing Matching Networks (Part 1: Networks with an LNA and Lumped Elements)Designing Matching Networks (Part 1: Networks with an LNA and Lumped Elements) uses the available gain design technique to design a low-noise amplifier for a wireless communication system.
Designing Matching Networks (Part 2: Single Stub Transmission Lines)Designing Matching Networks (Part 2: Single Stub Transmission Lines) shows how to design input and output matching networks for an amplifier.
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
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
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.
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.
Use the new gamma2z function to compute input impedance from a reflection coefficient.
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 are now available for any RF plot. For more information on data tips, see Data Cursor — Displaying Data Values Interactively in the MATLAB documentation.
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.
Modeling a High-Speed Backplane (Part 1: Measured 4-Port S-Parameters to a Rational Function Model)Modeling a High-Speed Backplane (Part 1: Measured 4-Port S-Parameters to a Rational Function Model) now uses the timeresp method to compute the time-domain response of a system characterized by measured data.
Modeling a High-Speed Backplane (Part 2: Rational Function Model to Simulink Model)Modeling a High-Speed Backplane (Part 2: Rational Function Model to Simulink Model) now includes code that you can use to generate a Simulink® model for any rfmodel.rational object.
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.
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.
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.
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.
"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.
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.
Use the extract function to extract specified network parameters from a circuit or data object and return the result in an array.
Use rfckt.rlcgline to construct an RLCG transmission line object.
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.
You can now read data from Touchstone data files that contain comments and spaces between sections of data.
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.
These objects can be used to store rfdata such as network parameters, noise figure, power, IP3, and spot noise.
The analyze method now takes three additional optional inputs for the load, source, and reference impedances.
|Release||Features or Changes with Compatibility Considerations|
|R2013a||Improved rationalfit function|
|R2010b||Enhanced Rational Function Modeling|
|R2009a||Enhanced Dielectric Loss Model in Three Transmission Line Objects|