Ansys HFSS: Shielding Effectiveness of an Enclosure Demo
Hello everyone, this is Adel from Ozen Engineering, Inc. Welcome to this demonstration of the shielding effectiveness of an enclosure using ANSYS HFSS.
Introduction
In this demo, we'll consider a PCB housing, which is a 3D component opened in HFSS. Let's explore the setup and results of the simulation.
Simulation Setup
- Open the 3D component in HFSS and expand the 3D Components section.
- Double-click to select the Boundaries tab.
- Apply a perfect E-boundary condition to the back and front of the geometry.
- Note the openings in the front where energy can enter.
Boundary and Excitation Setup
- Create a Phoebe boundary applied to the airbox.
- Under Excitations, set up two different optimizations for the box:
- Empty box
- Flat box
- Double box
- Specify incident wave excitations using spherical coordinate systems:
- One wave coming in along the x-axis
- One wave coming in along the y-axis
- Set polarization with theta = 1 for vertical polarization.
Analysis Setup
- Set the solution frequency to 2 GHz.
- In the Options tab, set the minimum number of passes to 5 for a good mesh.
- Configure a frequency sweep from 200 MHz to 2 GHz with 200 MHz steps, resulting in 10 plots.
- Set up a line that cuts through the enclosure from front to back for E-field plotting.
Results
After running the simulation, plot the E-field along the specified line. The complex magnitude of E in dB is shown as a function of distance.
- Outside the box, there are significant fields.
- Inside the box, at low frequencies like 200 MHz, there's minimal energy penetration.
- At 2 GHz, more energy enters the enclosure.
Effect of Copper Tape
By adding copper tape to seal some openings:
- Use rectangular sheets and apply a finite conductivity boundary condition.
- Plot results to see reduced energy penetration at higher frequencies.
- Check the E-field to confirm less energy enters due to sealing.
Complete Sealing
When the enclosure is completely sealed with copper tape:
- Significant fields remain outside the box.
- No energy penetrates inside.
Conclusion
This concludes the demonstration of the shielding effectiveness of an enclosure using ANSYS HFSS. Thank you for watching, and see you in the next video.
Hello everyone, this is Adel from Ozen Engineering and welcome to the Shielding Effectiveness of an Enclosure demo using ANSYS HFSS. So let's consider this PCP housing, a 3D component that I opened in HFSS.
If I expand 3D components, double click here, and select the Boundaries tab, we can see that a perfect E-boundary condition is applied to the back and front of the geometry. As you can see here in the front, we have some openings where the energy gets in.
After importing the geometry, we need to set up the simulation. Here, if I expand Boundaries, you can see that we have created a PEC boundary that is applied to this airbox. Under Excitations, we have the airbox, and we can see that we have a PEC boundary that is applied to this airbox.
We have two different optimizations for this box: the first one is an empty box, and the second one is a flat box. The third one is a double box. If you want to read the box, you can read the box.
We have set up incident wave excitations, and to set this up, we need to specify spherical coordinate systems where the waves are coming from. So here, we have one coming in along the x-axis and one coming in along the y-axis.
Also, we need to specify the polarization: here, we have theta equals one, so this is vertically polarized. Under Analysis, we have our solution frequency that is set to two gigahertz. Here, if I select the Options tab, we can set the minimum number of passes so it will have a good mesh.
In this case, we have set it to five. The frequency sweep was set up from 200 megahertz to 2 gigahertz with a 200 megahertz step, so we get 10 plots from this. Here, a line that cuts through the enclosure was set up; it goes from the front to the back.
After running the simulation, we can plot the E field along this line. Now, if I go under Results and double click here, we can see the complex magnitude of E in dB in function of the distance. So outside of the box, we can see the E field in function of the distance.
So outside of the box, we can see the E field in function of the distance. So outside of the box, we have a lot of fields, but inside of it, we can see that at low frequencies, like 200 megahertz, we have hardly any, but at two gigahertz, we have a lot of energy that gets in.
We can view this by plotting the E field. So if I double click on Complex MATE and animate it, we have a lot of field outside of the enclosure, and the higher the frequency, the more energy gets in. Now, let's see the effect if we add some copper tape to some of the openings.
We do that by adding rectangular sheets and applying a finite conductivity boundary condition. So if I go and plot the results, we can see now that less energy gets in at higher frequencies.
We can also check the E field, and as you can see, less energy gets in since we have sealed the energy in the enclosure. So we can see that the energy is going to be less. If we add some apertures, the last example, if we completely seal the enclosure, we apply the copper tape to all openings.
Now, if we check the results, we see that we have a lot of field outside of the box but nothing gets in again. We can see that here if we take a look at the E field complex mag E. This completes the Shielding Effectiveness of an Enclosure demo using ANSYS HFSS.
Thanks for watching, and see you in the next video.
