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Tapered Stripline (Closed Form): STAPER

Symbol

Topology

Parameters

STAPER$ is an iCell. See “Intelligent Cells (iCells)” for more information.

Name Description Unit Type Default
ID Element ID Text SL1
W1 Conductor width @ node 1 Length W[1]
W2 Conductor width @ node 2 Length W[1]
L Length of taper Length L[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.

Implementation Details

This is constructed out of a cascaded series of constant width Stripline transmission lines. The number of sections used is frequency-dependent and is constant as a function of the Length divided by the guided wavelength. The model assumes a TEM mode of propagation and incorporates the effects of dielectric and conductive losses. The parameters W1, W2 (Strip Widths) and L (Strip Length) are lengths entered in the default length units. The parameter SSUB specifies the Stripline Substrate element, which defines additional cross sectional parameters of the transmission line.

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

Zo>94.25/(εr)1/2 (for T≠0) 1≤εr Required
T/B≤0.1 Recommended Tand≥0 Required
Rho≤100 Recommended Ang≤45 degs or L≥|W1-W2|/2

0.05≤W/H≤20 Recommended

T/W≤0.5 Recommended

T/H≤0.5 Recommended

εr≤16.0 Recommended

1≤εr Required

Tand≥ Required

0≤Rho≤1000 Required

Rho≤100 Required

T/B≤0.1 Required

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] Cadence Design Systems, Inc. Developed Model. The references for the straight section Stripline model are shown below.

[2] H.A. Wheeler, "Transmission-Line Properties of a Strip Line Between Parallel Planes", IEEE Trans on Microwave Theory and Techniques, Vol. MTT-26, No. 11, November 1978 p.866-876

[3] S.B. Cohn, "Characteristic Impedance of the Shielded-Strip Transmission Line", IRE Transactions MTT, July 1954 p. 52-55

[4] H.A. Wheeler, "Formulas for the Skin Effect", Proceedings of the IRE September, 1942 p.412-424

[5] K.C. Gupta "Computer-Aided Design of Microwave Circuits", Artech House1981 p.60

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