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2 Suspended Substrate Edge Coupled Striplines (EM Quasi-Static): SS2CLIN



SS2CLIN models a section of two-edge coupled asymmetric stripline on a suspended substrate, that is, on a single layer substrate elevated over the infinite grounded plane.


Name Description Unit Type Default
ID Element ID Text TL1
W1 Conductor 1 Width- Nodes 1&&3 Length W[1]
W2 Conductor 2 Width- Nodes 2&&4 Length W[1]
S Gap width conductors 1&&2 Length W[1]
L Conductor length Length L[1]
Acc Accuracy parameter   1
SPSUB Substrate Definition Text SPSUB1[2]

[1] User-modifiable default. Modify by editing under $DEFAULT_VALUES in the default.lpf file in the root installation directory. See the AWR Microwave Office Layout Guide for details.

[2] Modify only if schematic contains multiple substrates. See “Using Elements With Model Blocks” for details.

Parameter Details

SPSUB. Suspended substrate parameters are listed in the SPSUB model description.

Acc. The Acc parameter is the accuracy parameter. The default value for Acc is 1. If Acc is less than 1 or greater than 10 it is set automatically to 2.

Parameter Restrictions and Recommendations

  1. Acc is limited to 1≤Acc≤10. A larger value of Acc increases the density of mesh used in computations. The accuracy of model parameters may gain slightly from increasing Acc at the expense of noticeable growth of computation time. Generally, a good trade-off between accuracy and computation time is to set Acc to 1.

  2. This component does not impose restrictions on the conductor thickness (thickness may be zero, positive, or negative). Negative thickness indicates that the conductor is recessed into the substrate.

Implementation Details

Model implementation is based on the EM Quasi-Static technique described in [1]. It accounts for losses in metal and in substrate dielectric. Dispersion is partly included.


This element uses line types to determine its layout. By default, the layout uses the first line type defined in your Layout Process File (LPF). You can change the element to use any of the line types configured in your process:

  1. Select the item in the layout.

  2. Right-click and choose Shape Properties to display the Cell Options dialog box.

  3. Click the Layout tab and select a Line Type.

  4. Click OK to use the new line type in the layout.

See “Cell Options Dialog Box: Layout Tab ” for Cell Options dialog box Layout tab details.

See “The Layout Process File (LPF)” for more information on editing Layout Process Files (LPFs) and to learn about adding or editing line types.

Recommendations for Use

NOTE: The implementation of EM Quasi-Static models relies heavily on the involved numerical algorithms. This may lead to a noticeable increase in simulation time for schematics that employ many such models.

If the thickness of any layer is too small in comparison with the thickness of another layer, simulation time may also noticeably grow.


[1] M.B. Bazdar, A.R. Djordjevic, R.F. Harrington, and T.K. Sarkar, "Evaluation of quasi-static matrix parameters for multiconductor transmission lines using Galerkin's method," IEEE Trans. Microwave Theory Tech., vol. MTT-42, July 1994, pp. 1223-1228.

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