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Microstrip Cross Junction (Closed Form): MCROSSX

Symbol

Topology

Parameters

MCROSSX$ is a Microstrip iCell and has no parameters. See “Intelligent Cells (iCells)” for more information.

Name Description Unit Type Default
ID Element ID Text MX1
W1 Conductor Width @ Node1&3 Length W[1]
W2 Conductor Width @ Node 2 Length W[1]
*W3 Conductor Width @ Node 3 (layout only) Length  
W4 Conductor Width @ Node 4 Length W1[1]
MSUB Substrate definition Text MSUB1[2]
*AutoFill AutoFill database if not equal to 0 Integer 0

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

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

* indicates a secondary parameter

The intelligent version of this model automatically assumes these widths are equal to the attached models at that node.

Implementation Details

This model implements an X-model of the microstrip Cross-junction. For a more detailed discussion of the X-models see EM-based Models (X-models). This model does not include the effects of dielectric, conductor or radiation losses, nor does it account for the effect of conductor thickness. Further, this model assumes that the widths at Port 1 and 3 are equal to W1.

Layout

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.

Restrictions

Independent Parameters: W1, W2, W4 and Frequency
Scalable Parameters: MSUB H- Substrate Height
Fixed Parameters: MSUB Er Nominal
Statistical Parameters: Er
0.25 ≤ Wwidest/H ≤ 4 Required εr nominal ≤ 16.0 Recommended
0.25 ≤ Wothers/Wwidest ≤ 1 1 ≤ εr nominal Required
0 ≤ Frequency ≤ Fmax Recommended (100*|εrr nominal|)/εr nominal ≤ 10% Recommended
  (100*|εrr nominal|)/εr nominal ≤ 20% Required

Wwidest = The largest dimension of W1, W2, and W4

Wothers = W1,W2, and W4 excluding Wwidest

FWmax=The frequency limits of this model are dynamic with respect to the dimensions of the discontinuity. This dynamic frequency limit is displayed to the user via warning messages for the relative size, and dielectric in use. Importantly, this recommended frequency limit will change as a function of the largest width in the discontinuity for a given substrate definition. The frequency limit warns the user that at least one of the transmission lines constructing the discontinuity is approaching the frequency where multiple modes can propagate. See “Upper Frequency Limitations” for more information.

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.

References

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

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