Coplanar Transmission Line C_LIN
Symbol :
Illustration :
Parameters :
L = Line length (stretchable)
C_LTYP = ID of coplanar transmission line applied at ports 1 and 2
C_SUB = ID of coplanar substrate definition
C_GRID = ID of simulation control data
TEMP = ID of element temperature definition used for noise computation
Notes/Equations/References :
- C_LIN represents a single coplanar line. The line dimensions are defined using the data item addressed by C_LTYP (see C_LINTYP). L is the line length. The substrate data are defined in data item addressed by C_SUB.
- A zero or negative value for L can be meaningful during the simulation. In such cases, the automatic layout generation works incorrectly and the generated layout has to be edited manually. The minimum value for L depends on the metal layer oversize in the currently selected foundry. In case of DEFAULT foundry, L should be greater than or equal to max(|cond_os|, |cond2_os|).
- C_LTYP is the ID of the line type data item in which the geometrical dimensions of the line are defined. See notations in chapter 4 (Important Note!) for the correct selection of C_LTYP.
Equivalent Circuit :
For the modeling of the C_LIN element, a distributive equivalent circuit is used and the model parameter are derived from quasi-static FD-calculations. There is no limitation due to the line dimensions. The DC and RF losses (represented by R´) due to the skin effect are calculated using the surface current distribution on the conductors. The dielectric loss of the substrate material (represented by G´, see also C_SUB) is also taken into account.
Layout :
- Different metallization levels can be used for the center line and the ground planes of a coplanar line.
- The layout of C_LIN is stretchable. Use menu point (Edit - Trace/Transmission Line - Stretch Transmission Line) in layout window in order to stretch the line.
- If the parameter GW_DEF in C_PROCES is set to a positive non-zero value, this value is used as ground width for layout generation (not for simulation).
