Learning Forum

[sumonasislam]

Hello, 

I am working on designing and characterizing a Reconfigurable Intelligent Surface (RIS). I am using Ansys HFSS to design and simulate the array and am currently trying to validate my process by comparing the results of the Antenna Array Setup (using a codebook file) against a manually created homogeneous finite array (with variable unit cell patch dimensions) with a feed antenna.

However, the radiation patterns / beamforming results from these two methods do not match in my current setup. I would appreciate your insights on whether my simulation methodology is correct or if I am missing critical configuration steps.

 

The simulation process is like this:

1.   First I create one unit cell with primary/secondary boundary, and assign floquet port and apply de-embedding to place the port at unit cell face.

2.  I sweep the patch dimensions and get the S11 magnitude and phase. I take Phases of all dimension combinations at 10 GHz frequency (operation frequency of the RIS) and make a phase vs dimension lookup table.

3.  Based on the required phase distribution for a target beam direction (e.g., θ = 30°, φ = 0°), appropriate patch dimensions are selected.

4. Then create the array manually. Add feed antenna and radiation boundary and complete simulation.

 

I am also including the power point version of this problem with reference images here for better understanding. Please feel free to ask if more information is required.

 

Any feedback, suggestions or reference will be very helpful and greatly appreciated. Thank you very much for your time and consideration.