Tutorial on CST

Workflow Example Patch Antenna Simulation

Purpose: 1. Understanding how to create and analyze an antenna @9.4 GHz

CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

New Projects - Project Templates Project templates are the preferred way to customize CST STUDIO SUITE automatically for a certain type of application.

Click on the Create Project Your already defined project templates are listed in the section "Project Templates".

If you haven't defined a project template for your application click on "Create a new project" to create one.

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Antennas Template Click on Antennas

Click on Next CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

Type of Antenna Click on Planar

Click on Next

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Solver Type

Click on Time Domain

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Units

Click on Next

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Summary of Project Template

Click on Finish

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User Interface

Let us show you...

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Design of Patch Antenna:Information What we need: 1) 2) 3) 4) 5)

Materials Patch – Radiating Element Substrate – Dielectric Ground Plane 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 CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

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.

CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

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. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

Patch Antenna Construction: Substrate Go to the 'Modeling' ribbon tab and create a brick with Rogers RT5880 . Type the below values in the opened window Click on brick button

Click on Escape button

L= 21.169 ts = 1.5 CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

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. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

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.

CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

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 coordinate 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. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

Patch (Radiating Element) Construction: Go to the 'Modeling' ribbon tab and create a brick with PEC Material.

Click on brick button

Lp : 9.79 Wp : 12.6 T : 0.017

Click on escape button in the key pad of your computer

CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

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. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

Coaxial Feed: Inner Pin Dimensions Click on escape button

Click on brick button

rad=0.45 mm Offset=1 mm ts and t already defined CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

Coaxial Feed: Dielectric Cylinder Turn the model to the back side of the substrate. A cylinder would have been protruded back with defined dimensions.

STEP 1: Pick bottom face of inner Pin and Align WCS on the selected face CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

Dielectric Cylinder: Dimensions

Click on cylinder button

Press Escape

Inner dielectric cylinder is created and highlighted in yellow color CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

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 CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

Mesh Settings Click on Global Properties

Click on Specials

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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

Now press the wave guide port icon and it automatically places the waveguide port. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

Boundary Conditions

Now press the icon boundaries and choose the above boundary conditions and then press ok button. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

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 choose E field and press ok. Now click on Farfield/RCS and then press ok. CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

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.

CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14

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) Click on Farfields: Click on Farfield (f=9.4)[1]

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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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Goal for Optimizer •Click on Goals Press on the Add New Goal button and it will open a new window . Now click on the result name arrow button and it will show various options. Choose the S11 template. In goal click on the arrow and select S1,1 template assign following condition: Move Min to 9.4 GHz

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Final Optimized Result

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CST MWS – Standard Workflow  Choose a project template.  Create your model.  parameters + geometry + materials

     

Define ports. Set the frequency range. Specify boundary and symmetry conditions. Define monitors. Check the mesh. Run the simulation.

CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com | May-14