# magnetic field magnitude

#1

hi, I want to simulate the H field distribution near a resonator. I put a frequency domain monitor near the resonator. I think the monitor gives results assuming the magnitude of the E field is 1. How can I make the monitors assume the magnitude of magnetic field is 1 instead of E field (I mean I want to get the results for magnetic field like the E field result). So basically what I want to see is the enhancement of each frequency component of the incident H field

#2

Did you try doing the excitation using a magnetic dipole instead of electric dipole?? The default of this option has the magnetic field magnitude equal to 1… Can this work for you?

#3

Thank you very much for your answer. Actually I am using a plane wave source and want to set the incident magnetic field amplitude to 1 in order to see the data on the frequency domain monitor without any manipulation.

Now I just divide the data on the frequency domain monitor by the H field magnitude of the plane wave (it is 2.654*10^-3) to get the enhancement factor. Is what I am doing correct? Is there any way to see the enhancement in the H field without any manipulation?

#4

It seems okay and makes sense. But I am not so sure. I think this page can be useful
https://kb.lumerical.com/en/solvers_fdtd_frequency_domain_normalization.html

#5

Hi,

The source E fields are normalized, meaning that injected E field amplitude=1.

We also know that H=E/Zo and that Zo for free space is ~120*pi

Therefore, if you set the amplitude of your source to be 120*pi, the injected H field amplitude will be 1, allowing for easy H field enhancement measurement.

Of course, Zo=120*pi is valid only for free space. If you use different background index, you have to adjust this accordingly.

Source setup:

H filed in free space as recorded by the field monitor: