Main Content


Parallel connected network


Use the rfckt.parallel object to create networks of linear RF objects connected in parallel that are characterized by the components that make up the network. The following figure shows a pair of networks in a parallel configuration.

Parallel configuration networks


circuit object and add function is recommended over rfckt.hybrid because the add function enables you to insert linear and nonlinear elements into a circuit object to create networks of any topology which includes a hybrid, an inverse hybrid, a parallel, and a series connected network. (since R2023b)



h = rfckt.parallel returns a parallel connected network object whose properties all have their default values.


h = rfckt.parallel('Ckts',value) returns a cascaded network with elements specified in the name-value pair property Ckts.


expand all

Computed S-parameters, noise figure, OIP3, and group delay values, specified as object. Analyzed Result is a read-only property. For more information, see Algorithms.

Data Types: function_handle

Circuit objects in network, specified as a cell array of object handles. All circuits must be 2-port. By default, this property is empty.

Data Types: char

Object name, specified as an 1-by-N character array. Name is a read-only property.

Data Types: char

Number of ports, specified as a positive integer. nportt is a read-only property. The default value is 2.

Data Types: double

Object Functions

analyzeAnalyze RFCKT object in frequency domain
calculateCalculate specified parameters for rfckt objects or rfdata objects
circleDraw circles on Smith Chart
extractExtract specified network parameters from rfckt object or data object
listformatList valid formats for specified circuit object parameter
listparamList valid parameters for specified circuit object
loglogPlot specified circuit object parameters using log-log scale
plotPlot circuit object parameters on X-Y plane
plotyyPlot parameters of RF circuit or RF data on xy-plane with two Y-axes
getopDisplay operating conditions
polarPlot specified object parameters on polar coordinates
semilogxPlot RF circuit object parameters using log scale for x-axis
semilogyPlot RF circuit object parameters using log scale for y-axis
smithPlot circuit object parameters on Smith Chart
writeWrite RF data from circuit or data object to file
getz0Calculate characteristic impedance of RFCKT transmission line object
readRead RF data from file to new or existing circuit or data object
restoreRestore data to original frequencies
getopDisplay operating conditions
groupdelayGroup delay of S-parameter object or RF filter object or RF Toolbox circuit object


collapse all

Create a network of transmission lines connected in parallel using rfckt.parallel.

tx1 = rfckt.txline;
tx2 = rfckt.txline;
rfplel = rfckt.parallel('Ckts',{tx1,tx2})
rfplel = 
   rfckt.parallel with properties:

              Ckts: {[1x1 rfckt.txline]  [1x1 rfckt.txline]}
             nPort: 2
    AnalyzedResult: []
              Name: 'Parallel Connected Network'


The analyze method computes the S-parameters of the AnalyzedResult property using the data stored in the Ckts property as follows:

  1. The analyze method first calculates the admittance matrix of the parallel connected network. It starts by converting each component network's parameters to an admittance matrix. The following figure shows a parallel connected network consisting of two 2-port networks, each represented by its admittance matrix.

    Two 2-port networks connected in parallel, each represented by its admittance matrix



  2. The analyze method then calculates the admittance matrix for the parallel network by calculating the sum of the individual admittances. The following equation illustrates the calculations for two 2-port circuits.


  3. Finally, analyze converts the admittance matrix of the parallel network to S-parameters at the frequencies specified in the analyze input argument freq.


[1] Ludwig, R. and P. Bretchko, RF Circuit Design: Theory and Applications, Prentice-Hall, 2000.

Version History

Introduced before R2006a