Simulation of Fresnel zone plate antenna in HFSS

Hello everyone,

I want to design a Fresnel zone plate antenna in HFSS. The design has two elements. (1) A plate having circular rings of different radii. It can be made by printed technology on RT/duroid 5880. and (2) horn antenna as a feed. My doubt is how can I simulate this complete design (plate+horn)? I have already designed a horn and also I have designed a plate having different radii. but I don't know which boundary excitation I should apply to this plate. Please help me.

Hi Kruti Gajera,

I'm not sure what you're asking. What do you mean by "boundary excitation"?

I mean to say how to assign excitation in a zone plate...



I want to simulate the plate as a reflector (by placing horn in front of plate) as well as a lens (by placing horn behind the plate). I want to know the steps for assigning boundaries and excitation for the plate part and then simulation results for combined design (plate+horn).

Assign a waveport excitation the the waveguide feed of the horn. Place the horn and the pate in a vacuum, where the edges of the vacuum box are at least a quarter wavelength away from the horn and plate. Assign a radiation boundary to all surfaces of the vacuum box. Measure S11.

Same as before, but look at the radiation pattern and compare to without the plate.

Im not sure how this differs from the first 2.

Hello PlanarMetamaterials,

Thank you very much for the solution. I will do it.

Kindly find the attachment here with file containing the image which is helpful in describing the complete design. In the first design, the plate is used as a reflector (case 1) and in second, the plate is use as a lens (case 2). In both the cases I want to simulate the complete design of (plate + Horn) and compare the results.

As I am new to HFSS, I am facing problems in understanding the boundary and excitation assignments for these type of structures. I am able to design a horn antenna by watching video tutorials and I have initiated the design of Plate which I have attached here ( Fresnel_zone_plate.rar), but I stuck on a boundary and excitation step. Please guide me. Thank you. :)

Hi Kruti Gajera,

Firstly, your image shows oblique incidence of the plane wave on the plate. Will you be doing this? If so, you most likely want to use an incident plane wave, not a waveport excitation.

To do this, right click on excitations in the left hand menu and select "Assign" -> "Incident Wave" -> "Plane Wave". You will then need to set up the incident angles.

To apply the radiation boundaries, right click on the main view screen and select "Select Faces". Then select each of the vacuum box faces (holding down control) and then right click again and select "Assign Boundary" -> "Radiation". The default settings should be ok.

Assign a waveport to your horn feed (make a sheet that covers the waveguide and assign a waveport to this sheet) but make sure that it is not excited (right click "Field Overlays" in the left menu, the "Edit Sources") when using in receiving mode. This will ensure that the fields received by the horn are properly absorbed.

You should be good to simulate now. Once completed, you can view the incident, total, and scattered fields in the sources window. By integrating power over the waveport surface (when scattered fields are selected), you can find the power received by the horn.

Good Luck