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Use the delay class to represent delay lines that are characterized by line loss and time delay.




h = rfckt.delay returns a delay line object whose properties are set to their default values.

h = rfckt.delay(Name,Value) sets properties using one or more name-value pairs. For example, rfckt.delay('Loss',2)creates an RF delay line with a line loss of 2 dB. You can specify multiple name-value pairs. Enclose each property name in a quote. Properties not specified retain their default values.


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This property is read-only.

Computed S-parameters, noise figure, OIP3, and group delay values, specified as a object. For more information refer, Algorithms.

Data Types: function_handle

Line loss value, specified as a positive scalar in dB. Line loss is the reduction in strength of the signal as it travels over the delay line.

Data Types: double

This property is read-only.

Object name, specified as a 1-by-N character array.

Data Types: char

This property is read-only.

Number of ports, specified as a positive integer.

Data Types: double

Amount of time delay introduced in the line, specified as a scalar in seconds.

Data Types: double

Characteristic impedance of the delay line, specified as a scalar in ohms.

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


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Represent delay lines that are characterized by line loss and time delay using rfckt.delay.

del = 
   rfckt.delay with properties:

                Z0: 50.0000 + 0.0000i
              Loss: 0
         TimeDelay: 1.0000e-11
             nPort: 2
    AnalyzedResult: []
              Name: 'Delay Line'


The analyze method treats the delay line, which can be lossy or lossless, as a 2-port linear network. It computes the AnalyzedResult property of the delay line using the data stored in the rfckt.delay object properties by calculating the S-parameters for the specified frequencies. This calculation is based on the values of the delay line's loss, α, and time delay, D.


Above, p = αa + , where αa is the attenuation coefficient and β is the wave number. The attenuation coefficient αa is related to the loss, α, by


and the wave number β is related to the time delay, D, by


where f is the frequency range 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