Learning Forum

[anz13556]

I am working on a slot antenna fed by a microstrip underneath. There are 5 layers: From the bottom: Dielectric2 -> Microstrip -> Dielectric1 -> Slot -> Dielectric1. Both dielectrics are lossless.

When I simulate the electric field, it looks like it's not radiating anything. What could be the issue? Is it a setup, design, or simulation issue?

[Takeshi Itadani]

Why don't you check S11? It is possible that the reflections are large and the antenna pattern is not being fed.
If it is the appearance of the plot that makes you think the radiation is low, why not check with Log Scale or dB?
Also, if you are plotting with Mag_E, you may want to check by animating the plot and changing the phase, or by plotting with ComplecMag_E.

[anz13556]

Thank you so much, your advice helped. 

I have another question. Without setting my plot to the log scale, I substituted my wave port with a voltage source, and my e-field plot looks better. What could be the difference between the voltage source and a wave port?

[anz13556]

Thank you so much, your advice helped. 

I have another question. Without setting my plot to the log scale, I substituted my wave port with a voltage source, and my e-field plot looks better. What could be the difference between the voltage source and a wave port?

 

[Takeshi Itadani]

Voltage Source is a way to force power to the edge you set.
Have you checked S11 when you set the Wave Port? It is possible that there is too much reflection and not enough energy being fed to the model. If so, review the Wave Port settings.