Tutorial on CST

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Workflow Example

Patch Antenna Simulation

Purpose:

1. Understanding how to create and

analyze an antenna @9.4 GHz

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New Projects - Project Templates

Project templates are the preferred way to customize CST STUDIO

SUITE automatically for a certain type of application.

If you haven't defined a project template for your

Your already defined project

Click on the Create

Project

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Antennas Template

Click on Next

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Type of Antenna

Click on Planar

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Solver Type

Click on Next

Click on Time

Domain

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Units

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Summary of Project Template

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User Interface

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What we need:

1)

Materials

2)

Patch – Radiating Element

3)

Substrate – Dielectric

4)

Ground Plane

5)

Coax Connector – Excitation

Important: Operating frequency of the antenna

• For tutorial purpose we have already calculated the parameters

responsible for designing the patch antenna at operating frequency of

9.4 GHz

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Material Assignment:

Click on load from

Library

Click on Use filter  Type Teflon in the Material tab and choose the Teflon material as

highlighted and please do the same for copper and load them.

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Material Assignment:

Click on Use filter  Type Rogers RT 5880 in the Material tab and choose the ROGERS

material as highlighted. Once you load them you can see the new material added in the

navigation tree.

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Patch Antenna Construction: Substrate

Go to the 'Modeling' ribbon tab and create a brick with Rogers RT5880 .

Click on Escape button

Type the below values in the opened window

Click on brick button

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Patch Antenna Construction: Ground Plane



Click on picks under Modeling Toolbar  Pick Face and select back

face of the substrate

Move the cursor on to the back part of the substrate and it will

highlight automatically the face. Double click on the face and it will

highlight the face as shown above in red color. If it doesn’t highlight

the face. Please repeat the above step again.

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Patch Antenna Construction: Ground Plane

Click on extrude button and it pops out new window and type the shown values. You should see a brown color on the back side of the substrate once this operation is over.

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Patch (Radiating Element) Construction:

Pick top face of the dielectric brick by using pick option under

Modeling Picks Pick Face

Activating and

Aligning the local

co-ordinate system

Press S or F and move the cursor on to the front part of the

substrate and it will highlight the face automatically. Double click

on the face and it will highlight the face as shown above in red

color. Once it gets highlighted go to modeling tab and choose the

align WCS option as shown in this slide.

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Patch (Radiating Element) Construction:

Go to the 'Modeling' ribbon tab and create a brick with PEC Material.

Lp : 9.79

Wp : 12.6

T : 0.017

Click on brick button

Click on escape button in the key pad of your computer

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Coaxial Feed: Inner Pin

Pick the mid point of the patch in the lower edge as highlighted in yellow color.

Now select Align WCS with selected point.

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Coaxial Feed: Inner Pin Dimensions

rad=0.45 mm

Offset=1 mm

Click on brick button Click on escape button

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Coaxial Feed: Dielectric Cylinder

STEP 1: Pick

bottom face

of inner Pin and

Align WCS

on the selected face

Turn the model to the back side of the

substrate. A cylinder would have been

protruded back with defined

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Dielectric Cylinder: Dimensions

Click on cylinder button

Press Escape

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Boolean Operation

Select ground from Components Tree  Click on Boolean Choose Insert and

then select diel_cyl_1.

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Coaxial Feed: Outer Conductor



Press

S

on the keyboard and now

move the cursor onto the

outer

face of the dielectric cylinder

it

will

highlight

automatically.

Double click on the outer face

and align WCS on the selected

face.

Click on

Extrude button

and type the

values shown

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Frequency Range

Click on Frequency and

type the shown values

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Mesh Settings

Click on Global Properties

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Excitation: Wave Guide Port

Go to the back side of the substrate and now press S or F and choose the bottom

face of the dielectric cylinder.

Inset view of the selected

face

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Waveguide Port Setup

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Boundary Conditions

Now press the icon boundaries and choose the above boundary

conditions and then press ok button.

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Field Monitors

Go to the field monitor tab

as shown below. Now right

click on the field monitor it

would show a new field

monitor as high lighted

Click on Frequency and type 9.4 in the frequency tab and

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Start the Solver

Now go to Home tab and Press

the T solver button.

It opens a new window as

shown in this slide. Now choose

the same settings and press

start button.

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Reflection Coefficient of Patch Antenna

Click on the S- Parameters folder and click on plus

symbol and it will display the S1,1 . Click on the

S1,1 and it will display automatically the above

result which is called reflection coefficient of the

antenna.

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E- Field Results

Click on 2D Results: Click on E field: Choose Abs of E

field

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Far Field (Radiation Pattern)

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Optimization of Feed Position

Click on Optimizer tab and

it will open the shown

window.

Now choose the offset and

click on the small window

present

beside

offset

parameter. It will put a

cross

mark

once

you

activate the small window.

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