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  1. #1
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    Coaxial feed of a microstrip antenna

    Hello,I am trying to make a coaxial feed to my circular patch antenna.
    As shown in the photos bellow i have created to metal cilinders one inside the other with dielectric cilinder spacing.
    The dimention are such that the inner pin touches the patch and the outer coating touches the ground plane.
    After ward with boolean operation i made the pin and the patch a single object,the outer coating and the ground a sigle object,
    made a waveguide port and ran the simulation.

    but its not working an showing really low directivity,if you could help me with a step by step manual which i could follow.
    (i have tried to follow both youtube video manuals)
    Thanks.

    Click image for larger version. 

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    •   Alt11th February 2017, 14:02

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  2. #2
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    Re: Coaxial feed of a microstrip antenna

    How many mesh cells between top and bottom metals of PCB? Maybe none? Then your connector sees short.



    •   Alt15th February 2017, 01:53

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  3. #3
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    Re: Coaxial feed of a microstrip antenna

    From the posted pictures is hard to understand where the mistake is.
    Try to follow the example below, and you will understand how to design a coaxial feed. Indications might not be exactly the same if you use a different version of the simulator.

    http://www.cc.ntut.edu.tw/~juiching/HFSS%20Probe.pdf



    •   Alt17th February 2017, 13:46

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  4. #4
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    Re: Coaxial feed of a microstrip antenna

    Hi antenna_beginner, I am a beginner too. I am working on HFSS not CST, but i believe the design should be same even with different softwares. In Coaxial/Probe feeding technique we subtract or remove a circular slot from ground plane and create 3 cylinders(probe, pin, coax) and a circle(waveport) but i am sure about making patch+inner cylinder and ground+outer cylinder as one object each.

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    Follow below clip on youtube to understand better:
    https://youtu.be/ntPqoZ2NI90



  5. #5
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    Re: Coaxial feed of a microstrip antenna

    Quote Originally Posted by qurratulayn View Post
    Hi antenna_beginner, I am a beginner too. I am working on HFSS not CST, but i believe the design should be same even with different softwares. In Coaxial/Probe feeding technique we subtract or remove a circular slot from ground plane and create 3 cylinders(probe, pin, coax) and a circle(waveport) but i am sure about making patch+inner cylinder and ground+outer cylinder as one object each.

    Click image for larger version. 

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    Follow below clip on youtube to understand better:
    https://youtu.be/ntPqoZ2NI90
    sorry i am *not sure about making patch+inner cylinder and ground+outer cylinder as single object each


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    •   Alt18th February 2017, 13:21

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  6. #6
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    Re: Coaxial feed of a microstrip antenna

    Dear all,
    please find in this link a tutorial for the coaxial feedline.
    Best regards!
    https://www.youtube.com/watch?v=Md-UeD6iWxs


    1 members found this post helpful.

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