Learning Forum

[Kristiyan Petkov]

Hello, I have to design the electromagnetic radiation of the tip of the probe of a microwave microscope and the reflection of this radiation at a semiconductor plate. The entrance signal at the tip should be 9 GHz, 1 mW and it should look something like this:

I tried to assign an excitation at the top part of the tip (voltage and tried also wave port) and then assigned boundary conditions to the rest of the cone -finite conductivity. I created a bigger box and assigned a radiation boundary to it, I only received an electromagnetic wave at the top of the cone (the bigger circle) and nothing on the sharp tip.

I will be truly grateful if someone can help me with the excitations and boundary conditions in order to receive guided radiation with the highest directivity towards the straight line from the tip to the semiconductor plate.

[Praneeth]

Hi Kristiyan,

Thank you for reaching out to the Ansys Learning Forum.

It looks like you are trying to design an antenna that radiates an electromagnetic field from the tip of the cone like structure. Please let me know if this understanding is correct. If not, kindly provide more information about your requirement.

Best regards,
Praneeth.
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[Kristiyan Petkov]

Dear Praneeth, 

Thank you so much for the reply. Yes, you are totally right I want to make an antenna. The cone-like structure is really close to the wafer and I have to make the cone act like an antenna with the highest directivity towards the silicon wafer and see how the wafer reacts (meaning the s11 parameter). But firstly I will be really glad if I can make the antenna work. Maybe somehow I need to simulate the nearfield of the antenna, but I don't know what excitation to use (wave port, lumped port, current, voltage, or anything else) nor what boundaries to apply. The only thing I know is that the signal should enter through the top of the cone (applied to the circle face on top of it) and that it is 9 GHz, and that the cone is made of gold surrounded by a box of air including both the cone and the silicon wafer in it.

 

[Praneeth]

Hi Kristiyan,

Are you trying to replicate the model from any reference literature?

If not, please note that a monocone antenna simulation setup would differ from what you mentioned in your post. It is recommended to go through a getting started guide on the monocone antenna setup under the Help menu. Alternatively, you can also go through the online help link - Ansys Electronics 2023 R1 - Monocone Antenna setup for detailed information. 

If you are new to antenna simulation in Ansys HFSS, then you can go through different example projects on Antenna category by using the open examples button on the Desktop ribbon area. You can also use Antenna toolkit ACT extension to create standard antennas which automates the simulation setup for your convenience. 

Best regards,
Praneeth.
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[Kristiyan Petkov]

Hi, 

Thank you so much for the response. The setup is taken from a task from my university. I have to simulate the electromagnetic waves from the tip of a probe of a microwave microscope and the final part is a cone. An example of this setup is shown in the picture: