planar multilayer substrate

Akash Moynul Hasan
Akash Moynul Hasan Altair Community Member
edited February 23 in Community Q&A

There is an extra layer generating in post feko but while designing in the cad feko it doesn't show up. why is this layer coming from? In addition, can I get insight knowledge of the construction of multilayer planar substrate. For example, I used copper on top and I used substrate in middle is there any layer in the Gound?  usually when we design antenna in the top it is copper, middle part is substrate and Gound is made of copper? in case of multilayer planar substrate with planar patch on top is there any ground plane? or it is substrate?  Thank you in advance.

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Answers

  • Torben Voigt
    Torben Voigt
    Altair Employee
    edited February 14

    Hi Akash Moynul Hasan,

    The "extra layer" that you see in POSTFEKO is a PEC ground plane you have defined in CADFEKO in the dialogue of the planar multilayer substrate:

    image

    As you can see in the picture, the ground plane is also visible in CADFEKO. The infinite groundplane can only be PEC, not copper. But of course you can also omit the inifite groundplane and define a finite surface made of copper as the groundplane instead.

    Examples of how to use the planar greens functions can be found in the Example Guide. For example, open the model of Example A8.3 "Pin-fed microstrip patch antenna with Multilayer Substrate" via the Application Macro in CADFEKO:

    image

    I hope this helps!

    Best regards,
    Torben

  • Akash Moynul Hasan
    Akash Moynul Hasan Altair Community Member
    edited February 14

    Hi Akash Moynul Hasan,

    The "extra layer" that you see in POSTFEKO is a PEC ground plane you have defined in CADFEKO in the dialogue of the planar multilayer substrate:

    image

    As you can see in the picture, the ground plane is also visible in CADFEKO. The infinite groundplane can only be PEC, not copper. But of course you can also omit the inifite groundplane and define a finite surface made of copper as the groundplane instead.

    Examples of how to use the planar greens functions can be found in the Example Guide. For example, open the model of Example A8.3 "Pin-fed microstrip patch antenna with Multilayer Substrate" via the Application Macro in CADFEKO:

    image

    I hope this helps!

    Best regards,
    Torben

    Thank you for your response.  Can I change the layer dimension so that it won't go outside of the substrate dimension? How can I choose copper as for patch and ground plane from feko? what is the main difference between regular antenna with patch+substrat+ground with this planar greens functions?  Thank you in advance.

  • Torben Voigt
    Torben Voigt
    Altair Employee
    edited February 14

    Thank you for your response.  Can I change the layer dimension so that it won't go outside of the substrate dimension? How can I choose copper as for patch and ground plane from feko? what is the main difference between regular antenna with patch+substrat+ground with this planar greens functions?  Thank you in advance.

    Hi Akash Moynul Hasan,

    As you can see in my attached picture the infinite PEC groundplane is visualized larger than the substrate layer(s), just like in POSTFEKO. Not sure why it is different for ? Which version are you using?

    Since I assume that you have no experience with Feko, I would recommend that you first watch the introduction videos and the Getting Started Guide. Then you should start building simple models from the example guide. Feko is quite intuitive and most customer learn it easily this way.

    image

    To apply copper to a face you need to add Copper from the Mediua Library to your model and then apply it to the face(s):

    image

    Best regards,
    Torben

  • Akash Moynul Hasan
    Akash Moynul Hasan Altair Community Member
    edited February 21

    Hi Akash Moynul Hasan,

    As you can see in my attached picture the infinite PEC groundplane is visualized larger than the substrate layer(s), just like in POSTFEKO. Not sure why it is different for ? Which version are you using?

    Since I assume that you have no experience with Feko, I would recommend that you first watch the introduction videos and the Getting Started Guide. Then you should start building simple models from the example guide. Feko is quite intuitive and most customer learn it easily this way.

    image

    To apply copper to a face you need to add Copper from the Mediua Library to your model and then apply it to the face(s):

    image

    Best regards,
    Torben

    Thank for your previous guidelines. Now I am able to use the copper from the library but still one questions is clear. Last time I might not be able to ask in an understandable way therefore I have attached a word file with my problem and questions. Please have a look and guide me with your answers. I appreciate your time and corporation. Thanks in advance.

  • Torben Voigt
    Torben Voigt
    Altair Employee
    edited February 22

    Thank for your previous guidelines. Now I am able to use the copper from the library but still one questions is clear. Last time I might not be able to ask in an understandable way therefore I have attached a word file with my problem and questions. Please have a look and guide me with your answers. I appreciate your time and corporation. Thanks in advance.

    Hi @Akash Moynul Hasan,

    Q1: The fact that the ground plane is displayed larger is only for the reason that the user can see it better. When using the "Planar multilayer substrate", all layers are infinite in the x and y directions. Planar greens functions are used so that no mesh is required for the dielectrics. This makes the simulation very fast.

    image

    Q3: Alternatively, you can define finite substrates by simply creating cuboids. This will then take longer. The example A8.3 "Pin-fed microstrip patch antenna with Multilayer Substrate" I mentioned before shows the use of the infinite layers, while the example "A.8.1 Pin-Fed, SEP Model" shows the same model using the finite substrate. Please take a look at it. It explains exactly what you are looking for.

    Best regards,
    Torben

  • Akash Moynul Hasan
    Akash Moynul Hasan Altair Community Member
    edited February 22

    Hi @Akash Moynul Hasan,

    Q1: The fact that the ground plane is displayed larger is only for the reason that the user can see it better. When using the "Planar multilayer substrate", all layers are infinite in the x and y directions. Planar greens functions are used so that no mesh is required for the dielectrics. This makes the simulation very fast.

    image

    Q3: Alternatively, you can define finite substrates by simply creating cuboids. This will then take longer. The example A8.3 "Pin-fed microstrip patch antenna with Multilayer Substrate" I mentioned before shows the use of the infinite layers, while the example "A.8.1 Pin-Fed, SEP Model" shows the same model using the finite substrate. Please take a look at it. It explains exactly what you are looking for.

    Best regards,
    Torben

    Thank you for your response. Now I am able to make similar dimension substrate and ground using cuboids but wanted to make similar one using Planar multilayer substrate. According to your answer for Planar multilayer substrate the PEC (ground) will always be larger than substrate so that it can see.  So, in that case while calculating the dimension I have to consider the extension part? or I can count it similar dimension as substrate size? Because usually the ground and substrate are same in dimension. I had one question last time about using copper in the ground plane instead of PEC while using Planar multilayer substrate. Is it possible?  Pardon me for creating confusion as I am writing research paper, so I have to clear those concepts and I will not get those answer anywhere except from you.  Thank you for being patient. 

  • Torben Voigt
    Torben Voigt
    Altair Employee
    edited February 23

    Thank you for your response. Now I am able to make similar dimension substrate and ground using cuboids but wanted to make similar one using Planar multilayer substrate. According to your answer for Planar multilayer substrate the PEC (ground) will always be larger than substrate so that it can see.  So, in that case while calculating the dimension I have to consider the extension part? or I can count it similar dimension as substrate size? Because usually the ground and substrate are same in dimension. I had one question last time about using copper in the ground plane instead of PEC while using Planar multilayer substrate. Is it possible?  Pardon me for creating confusion as I am writing research paper, so I have to clear those concepts and I will not get those answer anywhere except from you.  Thank you for being patient. 

    Hi Akash,

    As I wrote before, with planar multilayer substrates, the ground plane is only shown larger. It's just the visualization, not the actual size. All layers are infinitely extended in the x and y directions.

    Best regards,
    Torben