# Why are inductively coupled RFID systems put in certain frequency bands when there are no EM waves used?

LF - 125 kHz HF - 13.56 MHz

Those frequencies refer to the magnetic field that is used to induce a voltage in the transponder. Can the magnetic fields actually interfere with EM waves in the vicinity?

• I challenge you to create a 13.56MHz magnetic field without emitting EM – PlasmaHH Oct 10 '18 at 19:53

\begin{align} \nabla\cdot \textbf D &= \rho_V\\ \nabla\cdot \textbf B &= 0\\ \nabla \times \textbf E &= -\frac{\partial \textbf B}{\partial t} \\ \nabla \times \textbf H &= \frac{\partial \textbf D}{\partial t} + \textbf J \end{align}