triangular arrays

Hi everyone,
I need to simulate the square unit cell of a cpw-fed slot antennas array with master/slave boundaries in HFSS. The array lattice must be skewed of a distance d in order to suppress grating lobes due to the size (1.2λ) of the unit cell. This turns out to be a triangular lattice along the scan direction. I have always used master/slave boundaries with broadside regular arrays but I haven't used these boundaries for different lattices.

I kindly ask 4 ur help in order to solve my 'dilemma'.

The unit cell model of my array also contains 2 Floquet ports on the faces of the airbox opposite to the unit cell surface, representing the incident and the re-radiated plane wave respectively (I use Floquet ports instead od Incident Plane Wave Excitations 'cause I need to perform Dynamic Link Simulations in Nexxim).

Anyway, what are the correct settings for master/slave boundaries to reproduce such a situation? What about Floquet ports? Does anybody have any example file to show me for the use of M/Ss for skewed arrays?

Many thanks in advance.

Ivan

Hi all,
I've found out how to fix the problem for master/slave boundaries in skewed arrays. Instead of using a single master/slave at opposite faces of the airbox, it is necessary to use two masters on one face (with different widths, in order to reproduce the desired shift of surrounding unit cells) and two slaves at the other face (the order of slaves must be inverted respect to the masters). See the file to understand what I mean.

Now I have another problem. Since I need to simulate my unit cell including an amplifier inside the structure (there are two lumped ports in the middle of the cell), I need to simulate it with an Ansoft Designer Dynamic link. Thus, in order to represent the incident and the re-radiated waves, I need to use Floquet ports instead of radiation or PMLs at the upper and lower faces of the airbox, as u can see in the file (one port(1) to excite the receiving antenna and the other one (2) associated to the field which is reradiated by the orthogonal transmitting antenna). These Floquet ports will be appropriately connected to some microwave ports in Ansoft Designer, where I push the excitation to the HFSS model.

Now, after the validate check in HFSS I get the following error messages:

[error] Port 'FloquetPort1': The exterior boundary of the faces for a Floquet Port must consist of pairs of parallel and equal length segments, displaced from each other by an integer linear combination of the lattice vectors.

[error] Port 'FloquetPort2': The exterior boundary of the faces for a Floquet Port must consist of pairs of parallel and equal length segments, displaced from each other by an integer linear combination of the lattice vectors.

It's evident that the definition of the Floquet Ports doesn't match the lattice definition obtained by the particular use of the periodic boundaries.

Does anybody have any idea or know how to set Floquet ports correctly for this case?

Ivan

Doesn't matter. Problem solved!!!

could you share your experience on how to use floquet port and master/slave boundary to model triangular arrays? thx

Sure! But if you are interested in triangular arrays, master/slaves and Floquet just create a new topic on that subject and I will immediatelly reply. Sorry for that. I believe this is the most correct way. In case I will upload some example files. Let me know when u open the topic with a private message, for instance.

I.

can you share your experience with us?

good article from HFSS using floquet mode:
https://www.edaboard.com/ftopic169368.html#1115836

Dear Burton,
you may find answers at the following link, where I posted a reply to a similar topic:

https://www.edaboard.com/ftopic340872.html

can you help me in the choice of dimension related to the wave port in hfss??

I am trying to calculate reflection phase for patch reflectarray and i want to compute the reflection phase using floquet ports.
I have simulated the reflectarray structure using waveguide simulator approach and already got reflection amplitude and phase.
I am trying to use floquet ports to excite similar TE10 mode and compare my results.

Any suggestion are welcome.

thank you

Dear harishbigh, there are different ways for simulating the situation u are interested in, either with floquet ports and or plane waves. You'd better open a new topic, specifically addressed to the problem you are facing and I will try to help you. When you have started the topic, please send me a pm the so I can reply as soon as possible.

I.

try this!

Use maser/slave boundaries (leave the phase delay to be zero)
place Floquet port, the phase delay (theta and phi) determines direction of incident field (phase delay of master slave boundaries automatically will be set), in floquet port setup choose the modes which u want, choose 3D refinement for at least one of them, use de-embeding to extract the S-param of the the surface
Use interpolating or discrete simulation
S11 is equal to reflection coefficient of port #1 (because the ports in HFSS are always matched)

Here is an example

good luck

Dear Ivan,

Can you share your experince on this platefrom so that everyone will be beneficial from your finding. If u do not then kindly send methe rpivate message how you solved the problem to set the floquets port. Actually i want to simulate my HFSS stacked patch unit cell and for that i need to use this port.

Thanks in advance.

Hi guys. Can you help me. I am not sure the form of the unit cell for my array is correct. Can you check it please. See image i add.
../imgqa/eboard/EM/EM-cpv5eqrk1yh.jpg