Main Content

# rfckt.delay

## Description

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

## Creation

### Description

example

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.

## Properties

expand all

This property is read-only.

Computed S-parameters, noise figure, OIP3, and group delay values, specified as a rfdata.data 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

 analyze Analyze RFCKT object in frequency domain calculate Calculate specified parameters for rfckt objects or rfdata objects circle Draw circles on Smith Chart extract Extract specified network parameters from rfckt object or data object listformat List valid formats for specified circuit object parameter listparam List valid parameters for specified circuit object loglog Plot specified circuit object parameters using log-log scale plot Plot circuit object parameters on X-Y plane plotyy Plot parameters of RF circuit or RF data on X-Y plane with two Y-axes getop Display operating conditions polar Plot specified object parameters on polar coordinates semilogx Plot RF circuit object parameters using log scale for x-axis semilogy Plot RF circuit object parameters using log scale for y-axis smith Plot circuit object parameters on Smith chart write Write RF data from circuit or data object to file getz0 Calculate characteristic impedance of RFCKT transmission line object read Read RF data from file to new or existing circuit or data object restore Restore data to original frequencies getop Display operating conditions groupdelay Group delay of S-parameter object or RF filter object or RF Toolbox circuit object

## Examples

collapse all

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

del=rfckt.delay('TimeDelay',1e-11)
del =
rfckt.delay with properties:

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

## Algorithms

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.

$\left\{\begin{array}{c}{S}_{11}=0\\ {S}_{12}={e}^{-p}\\ {S}_{21}={e}^{-p}\\ {S}_{22}=0\end{array}$

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

${\alpha }_{a}=-\mathrm{ln}\left({10}^{\alpha /20}\right)$

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

$\beta =2\pi fD$

where f is the frequency range specified in the analyze input argument freq.

## References

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

## Version History

Introduced before R2006a