intuition for model magnetic field manipultion

The magnetic fields are directly linked to the currents on the surface of the conductor (\vec{J} ~ \hat{n}\times\vec{H}, etc.).
If you want the magnetic fields strongest on the outer circumference, this is where your currents need to be. It looks like you are going for a narrow-band resonant system, so this should be doable. Perform an eigenmode (or similar) simulation at lower frequencies to find where such a resonant mode exists.

You may need to break physical symmetry to excite such a mode, hopefully this isn't a problem.

Hello, my current density is as shown below.
My magnetic field is flowing around this current.
Could you give me intuitions regarding how changig the shape of resonator will affect the current?
And most importantly how the change in current will affect the magnetic field around it?
Thanks.

It looks like this is a simple "TM10" type half-wave resonance, similar to a patch antenna. If you want currents on the outer edge, I'd suggest rotating the structure 90 degrees with respect to the magnetic field; likely you'll also need to adjust its electrical size.

My other main two suggestions are to:

1. Find other resonant modes of this structure. There may already be one that has similar properties to what you want.
2. Break physical symmetry to couple with various incident magnetic field modes.

PlanarMetamaterials said:

The magnetic fields are directly linked to the currents on the surface of the conductor (\vec{J} ~ \hat{n}\times\vec{H}, etc.).
If you want the magnetic fields strongest on the outer circumference, this is where your currents need to be. It looks like you are going for a narrow-band resonant system, so this should be doable. Perform an eigenmode (or similar) simulation at lower frequencies to find where such a resonant mode exists.

You may need to break physical symmetry to excite such a mode, hopefully this isn't a problem.

Click to expand...

Hello PlanarMetamaterials,basickly its a Patch.
I need the magnetic field as strong as possible above the patch.
In the situation below the magnetic field is strongest between the patch and gnd.
I want to make the magnetic field above stromnger.
How do you think i should break simetry and what is the physical intuition behind it?

Generally, structures exhibitng bilateral symmetry often possess fundamental resonant modes with equal and oppisitely-directed dipole moments. This causes the mode to respond exceptionally weakly to external fields (these are sometimes referred to as "dark" modes in optics).

Breaking the symmetry disallows the existince of these equal and opposite fields, and therefore the structure can better interact with external fields.

For "stronger fields" I'm not sure what to say. At resonance, the magnetic and electric fields should possess the same energy; you simply want to ensure the magnetic energy is being stored above the structure. I suggest investgating ways to "cancle out" the magnetic fields below the structure, such that the bul of the fields will be above the upper surface.

Alternatively, you could investigate methods of coupling more incident power into the structure, but you may already have good matching. Perhaps investigate this by exciting near-magnetic fields with an H-field probe or hertzian dipole?

Good Luck!