modelTLine

Lossless transmission line with characteristic impedance Z0 and transmission delay TD

Extends from Modelica.Electrical.Analog.Interfaces.TwoPort (Component with two electrical ports, including current).

Information

Lossless transmission line with characteristic impedance Z0 and transmission delay TD. The lossless transmission line TLine is a two Port. Both port branches consist of a resistor with characteristic impedance Z0 and a controlled voltage source that takes into consideration the transmission delay TD. For further details see [Branin1967]. The model parameters can be derived from inductance and capacitance per length (L' resp. C'), i. e. Z0 = sqrt(L' / C').

There are three possibilities for specifying the transmission delay TD:

  • Calculate TD = sqrt(L' * C')*length_of_line.
  • Specify the normalized length NL, i.e. the length of the line divided by the wavelength corresponding to the frequency F: TD = NL / F.
  • Specify NL = 1/4, i.e. the length of the line is assumed to be equal to a quarter of the wavelength corresponding to the frequency F: TD = 1/4 / F. In that case, the characteristic impedance Z0 is called natural impedance.

Resistance R' and conductance G' per meter are assumed to be zero.

References: [Branin1967], [Hoefer1985]

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.ResistanceZ0Characteristic impedance
Modelica.Units.SI.TimeTD0Transmission delay: specify > 0 if F and NL are not given
Modelica.Units.SI.FrequencyF0Frequency: specify > 0 if TD is not given
RealNL1/4Normalized length: specify if TD is not given

Connectors

TypeNameDefaultDescription
PositivePinp1 (from FourPin)Positive electrical pin of port 1
NegativePinn1 (from FourPin)Negative electrical pin of port 1
PositivePinp2 (from FourPin)Positive electrical pin of port 2
NegativePinn2 (from FourPin)Negative electrical pin of port 2

Components

TypeNameDefaultDescription
SI.Voltagev1 (from FourPin)Voltage drop of port 1 (= p1.v - n1.v)
SI.Voltagev2 (from FourPin)Voltage drop of port 2 (= p2.v - n2.v)
SI.Currenti1 (from FourPin)Current flowing from pos. to neg. pin of port 1
SI.Currenti2 (from FourPin)Current flowing from pos. to neg. pin of port 2
Modelica.Units.SI.VoltageesVoltage source of forward travelling wave
Modelica.Units.SI.VoltageerVoltage source of reflected wave

Revisions

  • 1998 by Joachim Haase
    initially implemented