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SGap (EM Base): SGAPX



The SGAPX element models the electrical characteristics of a gap in the signal conductor for a stripline transmission line system. The model is based upon multiple full wave electromagnetic simulations performed on the present substrate configuration. As the results of these EM simulations are stored, these lengthy simulations only have to be performed once.

SGAPX$ is the corresponding intelligent cell (iCell). An iCell model is identical to its non-iCell equivalent with the following exception: Certain dimension-related parameters are not explicitly specified by the user; rather, they are automatically and dynamically determined by the dimensions of the attached elements. See “Intelligent Cells (iCells)” for a detailed discussion of how to use iCells, their advantages, and their limitations.



Name Description Unit Type Default
ID Name Text TL1
W Conductor width Length W[1]
S Gap width Length W[1]
SSUB2 Substrate definition Text [2]
*AutoFill AutoFill database if not equal to 0   0

[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.

* indicates a secondary parameter

Parameter Restrictions and Recommendations

  1. 0.025≤S/B≤0.5 Recommended

  2. 0.1≤W/B≤2.0 Recommend

  3. 0.1≤H1/H2 and 0.1≤H2/H1

  4. B=H1+H2 with H1 and H2 defined in SSUB2

Implementation Details

SGAPX is implemented as an EM-based model, or "X-model". An X-model is based on stored full-wave EM simulations and is the most accurate of models available. See EM-based Models (X-models) for a detailed discussion of X-models, their advantages, and their limitations.


This element does not have a visual layout cell. The layout cell creates a gap between the two microstrip or stripline elements that connect to each side. The size of the gap is determined by the S parameter. Since there is no layer to draw, linetypes do not apply. You can select the layout cell to snap the microstrip or stripline elements to it.

Recommendations for Use

Discontinuity models function most accurately when attached to lines that match their corresponding edges. Directly connecting discontinuity models to one another reduces their accuracy.


This model was developed under research performed at Cadence Design Systems, Inc. The full set of details of the implementation are considered proprietary in nature

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