Frequency Domain Equation

To derive the time-harmonic equation this physics interface solves, start with Ampère’s law including displacement currents (then called Maxwell-Ampère’s law), as these do not involve any extra computational cost in the frequency domain,

Now assume time-harmonic fields and use the definitions of the fields,

and combine them with the constitutive relationships B = μ0(H + M) and D = ε0E to rewrite Ampère’s law as