Both of their units are A/m, yet both seem to be different! What is the difference?
Surface current density and magnetic field intensity both have same units A/m. They are related using boundary condition as follows:
The tangential magnetic field across 2 different media is discontinuous at the interface, and is numerically equal to surface current density. In mathematical notation:
n X (H2 - H1) = Js..
This gives both of them same units.
For a perfect electric conductor, field inside it H1 = 0.
Therefore,
n X H2 = Js
That means- tangential component of magnetic field on the surface of a conductor is equal to the surface current flowing through the conductor.
You can go through derivation of those equations for clarity
Surface Current Density is nothing but surface current per unit area (A/meter2). Magnetic flux intensity is current per unit length (A/meter).
http://www.coolmagnetman.com/magfund06.htm .
https://www.quora.com/What-is-magnetic-field-intensity
Difference between your height and size of the house? Both of their units are cm, yet both seem to be different! What is the difference?
Anveshkumar Nella: Thanks for the answer, but please take a look at both Pozar (Microwave Engineering) and your HFSS software.
Jsurf and H Field have the same units (A/m), where Jsurf is called as electric surface current density. What you have mentioned is volume current density which has a unit of A/meter2.
Surface current density and magnetic field intensity both have same units A/m. They are related using boundary condition as follows:
The tangential magnetic field across 2 different media is discontinuous at the interface, and is numerically equal to surface current density. In mathematical notation:
n X (H2 - H1) = Js..
This gives both of them same units.
For a perfect electric conductor, field inside it H1 = 0.
Therefore,
n X H2 = Js
That means- tangential component of magnetic field on the surface of a conductor is equal to the surface current flowing through the conductor.
You can go through derivation of those equations for clarity
Yes, I kinda remember the derivation. But, what is electric surface current density?
Is it the flow of current density along a surface?
The units thus can be A/m2 * m = A/m? Please correct me if I am wrong!
Surface current density lumps together all the current from different (small) depths, so is not A/sqm (current density) but A/m (surface current density). In most RF the current is in a very small skin depth that is only a few microns (GHz) or tens of microns (MHz), so is treated as if it is a zero-thickness sheet. The actual thickness does make a difference sometimes, particularly at lower frequencies, for instance in the inductance of single wires, because some magnetic field penetrates into the wire to the same depth as the currents (the magnetic field is equal to the integral of the current density remaining below it).
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