Delay line
Use the delay
class to represent delay lines that are
characterized by line loss and time delay.
h = rfckt.delay
h = rfckt.delay('Property1',value1,'Property2',value2,...)
h = rfckt.delay
returns a delay line object whose
properties are set to their default values.
h = rfckt.delay('Property1',value1,'Property2',value2,...)
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
analyze | Analyze circuit object in frequency domain |
calculate | Calculate specified parameters for circuit object |
circle | Draw circles on Smith Chart |
listformat | List valid formats for specified circuit object parameter |
getz0 | Characteristic impedance of transmission line object |
listparam | List valid parameters for specified circuit object |
loglog | Plot specified circuit object parameters using log-log scale |
plot | Plot specified circuit object parameters on X-Y plane |
plotyy | Plot specified object parameters with y-axes on both left and right sides |
polar | Plot specified object parameters on polar coordinates |
semilogx | Plot specified circuit object parameters using log scale for x-axis |
semilogy | Plot specified circuit object parameters using log scale for y-axis |
smith | Plot specified circuit object parameters on Smith chart |
write | Write RF data from circuit or data object to file |
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 + iβ, 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.