C_LIN Coplanar Transmission Line Parameters Notes Equivalent Circuit Layout
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Coplanar Transmission Line C_LIN represents a single coplanar line. The line dimensions are defined using the data item addressed by C_LTYP. L is the line length. The substrate data are defined in data item addressed by C_SUB.

Parameters  

Notes

• 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.
• If L1 in selected C_GRID is not set to –1 or –2 (auto sizing), the minimum values for L1 is:

  L1min=W+2S+2GW

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. 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 TAND in 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).