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Stripline Bend Optimally Mitered, 90 deg (Closed Form): SMITER

Symbol

Topology

Parameters

SMITER$ is an iCell. See “Intelligent Cells (iCells)” for an explanation of iCells.

Name Description Unit Type Default
ID Element ID Text SL1
W Conductor width Length W[1]
SSUB Substrate definition Text SSUB[2]

[1] User-modifiable default. Modify by editing under $DEFAULT_VALUES in the default.lpf file in the root installation directory.

[2] If only one SSUB is present in the schematic, this substrate is automatically used. If multiple SSUB substrate definitions are present, you must specify which to use.

Implementation Details

This circuit component models an optimally mitered 90o bend in the Stripline center conductor. This circuit component is modeled by a section of straight section of transmission line of characteristic impedance equal to that of a strip of width W. The model includes the losses associated with the conductor and substrate. The formula below should be used to determine the value of the dimension "a" of the chamfer. Note, the reference planes for the two port changes depending upon the value of W/a. The parameter W1 (Strip Width) is a dimension entered in the default length units. The parameter SSUB specifies the Stripline Substrate element, which defines additional cross sectional parameters of the transmission line.

Use Reference Plane (a) if a/W≤1.0

Use Reference Plane (b) if a/W ≥1.0

If W/B≤0.2(B≡Ground Plane Spacing)

if 0.2≤W/B≤1.6

if if 1.6≤W/B≤14.25

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

W/B≤14.25

T/B≤0.1 recommended

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

[1] G. Matthaei, L. Young, E.M.T. Jones "Microwave Filters, Impedance-Matching

[2] Networks and Coupling Structures", Artech House, Inc. 1980 pp 203,206.

[3] Harlan Howe, Jr. "Stripline Circuit Design", Artech House, Inc. 1982

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