Ozen Engineering Webinar: SBR Plus Solver in HFSS

You're welcome, everybody. This is Steven. Today's topic will be ANSYS HFSS SBR Plus Solver in AEDT. The purpose of today's seminar is to show how Solver works and to introduce some features to the audience. So it's really a webinar for those who haven't had as much experience in Solver in the past.

Steven, sorry to interrupt here. I just want to let you know that your voice is kind of going in and out. If you're able to adjust your microphone that might be helpful. Is this better? It sounds better, yes. Okay. Okay. Okay. So let me show what we'll see in today's webinar.

We'll see how you set up a RCS simulation in SBR Plus and how to control the simulation. How to plot a visual ray trace in the AEDT environment and what kind of filters we can do with those rays, and possibly the linked excitation blockage feature introduced as well.

A quick overview of what is a SBR Solver. First of all, the SBR stands for Shooting and Bouncing Rays. It's an asymptotic solver that extends the Physical Optics to Multiple Balances by Geometrical Optics rays.

NSS has extended the traditional SBR definition to SBR Plus, which adds two extra features. It adds Diffraction physics to the general SBR. Those two are the Physical Theory of Diffraction, as well as the Uniform Theory of Diffraction. And then, the SBR solver is the UTD.

So the main purpose of this SBR solver is to calculate scattered fields by using Shooting and Bouncing Rays. How SBR works, first of all, it needs a source. And then, we need a scattered geometry. Then, we'll need an observation point. The source shoots a bunch of rays to a scattered geometry.

As you can see, this helicopter, the green area represents the rays that's being shooted onto the scattered geometry. And then, it will plot a surface current on the scattered plane.

The color and the dots on represented on the geometry is mainly the scattering points where the rays are being shooted onto. And at the edge of the geometry, there will be diffraction. That's where this will be corrections due to the edge currents applied. The edge currents will also radiate.

And the edge diffraction rays launched if it is enabled. So the currents will be painted due to the ETD rays. So the currents painted by the SPR rays corrected at the edge plus the painted by the UTD rays will be summed together and give a whole plot of the painted currents.

Of course, the rays will be balances around multiple times. So there will be multiple balances on the geometry. The fields added coherently at the observation point at every balance. So that gives an entire plot of the currents after multiple balances of SPR and the UTD rays.

The accuracy of the SPR plus simulation determined is is directly determined by the ray density. The lower the density, the larger the footprint is. The bigger the ray density, the smaller the footprints are. And the accuracy is decreased as the accuracy increases as the ray density increases.

How do we control the SPR solution setup in the EEDT? There are several things we can control for the solver. As we mentioned before, there's ray density per wavelength. There is also the maximum number of balances you can specify. So you can calculate the accuracy of the solution.

Also, as we mentioned before, the PTD and the UTD simulation setup, at default, is a none. You can also have PTD correction as well as PTD correction plus UTD arrays. But it doesn't mean that SBRplus doesn't need a meshing. We do need a meshing for this solver. So we start off with a flat set faces.

And then on the curved side, we can see we will need to turn on this allow tolerant meshing for SBRplus objects. As you can see for the tolerant meshing on the top surface, it is finely meshed, where the not tolerant is very weak.

The ray footprint is correlated to the mesh triangle, as you see on the green triangle represents the mesh represents the ray footprint. There are two ways to access SBRplus solver in AEDT. Backing the R19. 0. The SBRplus region was introduced.

So it could be a hybrid region in the driven model analysis. And then later in R19.1, SBRplus solver was introduced. In that setup, all the regions will be SBRplus region and no ports will be allowed, meaning as you can see, there is no port field display in the SBRplus solver.

So it's a very simple solution. We can have a couple of boundary conditions we can have in SBRplus. So in other words, in SBRplus region can be assigned the following boundaries.

Finite connectivity, perfect E, perfect H, impedance or layered impedance boundary, and lastly, a newly added boundary condition, Fresnel boundary. The SBRplus region. So we can have a couple of different kinds of excitations being can be implemented in SBRplus. We can implement a plane waves.

We can also use a length excitation from an outside source. For example, we can use those halfway dipole parametric beam, parametric slot, and et cetera. Can also use parametric antennas. So let's take a look at an example we already have of the RCS. It's a trihedral corner reflector. It's metallic.

It's the size of about 20. The size of it is about 20 lambda of the frequency of the wavelength. So we compute a monostatic RCS and we'll just go through it. And then we'll go through the other components. So we can see that the RCS is a monostatic RCS.

And then we can see that the RCS is a monostatic RCS. And then we can see that the RCS is a monostatic RCS. And then we can see that the RCS is a monostatic RCS. So that's pretty much all. Thank you. So that just shows you how the SPR-plus results compare to the full wave solver integral region ...

the integral equation IE solver and the impact of different simulation settings. Next slide, please. Are you ready? Yes, I'm sure the experience is worth it. Basically, these are... Let me push the Slovenian mengel похож. And the solution ofión foreign language. Hi, everyone. Okay.

So we have a, this is a, trihedral RCS setup. Let's take a look at different setups we have here. So as you can see, this is SVRplus solution setup. So we have a perfect reflection of a perfect E boundary condition. We're trying to calculate the RCS at the XY plane.

So we give an incident wave excitation. That's in the XY plane. We all see how different settings, that gives you different results. We have a SVRplus solution setup. So we have a perfect reflection of a perfect E boundary condition. We're trying to calculate the RCS at the XY plane.

So we give an incident wave excitation. That's in the XY plane. We all see how different settings, that gives you different results. We have a SVR plus, SVR setting. It's the 1. It's perineum here as well as a, SVR setting, where it's UTD, PTD.

One thing we need to pay attention to is that the default for comparedelen BBCT. How do you turn it on ExactT креп jeunesse a OL FERB. First, let's take a look at with or without the diffraction. There are two similar plots. One is with the diffraction, one is without the diffraction.

As you can see, there's not much big difference. Without diffraction, results takes only four seconds to solve. Well, with the diffraction option, it takes about five more times, about 19 seconds to complete. But the results doesn't have much big of difference.

But what if we take a look at the difference between these two other SPR solvers with full width solvers? Now it's still not much of a big difference, but the full width solver takes way much longer. As you can see, 36 minutes to complete, where the previous two is four seconds, it's 19 seconds.

So these are just with the default settings. So now we have the default settings. So now we have the default settings. So now we have the default settings. So now we take a look at... We make a variable for... So let's take a look at the...

Compare the difference between the different rate density settings. So we set a max number of bounces at five, whereas different rate density... So rate density... So rate density at two takes one second to complete.

Rate density at four takes four seconds to complete, and rate density at eight takes 60 seconds to complete. So rate density at two takes one second to complete, and rate density at eight takes 16 seconds to complete. As you can see, not much of a big difference either.

Today we're going to look at some of the minuses with the substitute racation effect, and pan vaccine. Then we can take a look at how many... We can set the maximum number at... Rate density at four fixed was different max bounces. So we can set the maximum number Ath pues pues rodares.

I think you know what I'm saying actually.

The maximum balance is so now we can this is where it makes up makes a difference the maximum balance is for for one balance two rounds three bounds and five pounds so all of them takes pretty takes pretty quick just couple seconds to complete but the results is fairly different so after that we can I can show you how to plot the visual ray trace which we have so we can do that I go to field overlays plot VRT but and click on SPR and we'll just take everything as default and so now initially when we click on that there will be an arrow saying the visual ray trace is too close to the cat surface so we want to change the observation point so we go to the we go to the visual ray trace SPR we go to plot that we just plotted the first plot was pre was was already plotted before the presentation the plot 2 was the one that I just created we can change the coordinate to change the the source that's it at 50 right so it was aborted at the first but now it's since we changed the source location now it's all set to go a couple things we can play with so we can change the rate rate density now it's at 2 we'll come change it to 8 maximum number of bounces well first of all let's let's try to understand what what's what's in this plot if we go to the the top go to the top menu of the ray tracing plot it will tell you that the with the color represents so right now the color represents the number of flex reflections the green means one reflection blue represents two reflection yellow is three red is four and we can define the color by with different definition now it's number of reflections we can change it to number of trans transmission we can also define the balance number um we can so this draw exit was turned on we can turn it off so if we turn this on all we're seeing is the exit uh exit rays we can also uh if you don't want to see them as lines we can draw them as points so there will be showing you scattering points of those rays you can also draw Ray footprints so those are something we can we can play with on the top menu on a on the very very on the plot itself um we can change the rate density that's per Lambda um we'll have the maximum frequency you can change with what else can we change um right we can and there is a filter uh number of bounces if we turn this off this will be the entire uh the entire uh source if we give a criteria initially was at zero and it was this is at one this will be all the uh incident race so if we don't want to see any incident waves we can change this to one and now everything we see will be the rays exiting the reflector uh we can also so foreign we can also give a filter to the shoot filter so we can define a we already have two boxes defined it's a non-model box for the box for the inner box we click on inner box and we go to the plot we click on Ray's in box box signal this will be the the race they're shooting off from inside the box and we'll also have a box outside of the reflector I choose box outer this will be a race shooting out of the box so those are some of um the capabilities we can play with in the AEDT for SBR plus solver if you have any questions uh please feel free to post it in the question section otherwise this will be all I have for today's webinar um thank you very much for joining today have a nice day we'll talk again very soon.