## General

#### How to calculate the values of E and H fields on the surface of an object solved as IE region (or in HFSS-IE design)?

• Solution
Participant

If an object is solved using IE solver, the E and H fields are not available through the standard field reporter. The IE solver is used either in HFSS-IE design or inside FEM design if the object is assigned as IE hybrid Region. The standard fields reported in these case are electric and magnetic surface current densities and charges: J, Jm,Q,and Qm. It is possible to use Maxwell equations to reconstruct values of Electric and magnetic fields on the surfaces if necessary. For example, for metal object solved with IE solver: â€¢Magntic current and charge density are equal to zero: Jm=0, Qm=0 â€¢As we assume E and H fields inside the conductor is 0, from Maxwell equations: â€¢n dot D = Q, where D=Îµ*E â€¢For metal object in vacuum: E_normal to surface = Q/Îµ _o â€¢n cross H = J â€¢For lossy metal object in vacuum: H_tangential to surface = J, E_tangential can be calculated using surface impedance definition: â€¢E_tangential to surface = Zs*(n cross H_tangential to surface), where Zs is a surface impedance: Zs=(1+j)/(conductivity*skin_depth) â€¢ Note that for good conductor the surface impedance is very small compared to free space (for copper at 1GHz : (8e-3)*(1+j) Ohm, so the value of E_tangential is expected to be very small compared to E_normal