The present application discloses embodiments that relate to an electromagnetic apparatus. In one aspect, the present apparatus includes a circuit board configured to propagate an electromagnetic signal, a waveguide configured to propagate an electromagnetic signal, and a coupling port configured to couple the electromagnetic signal between the circuit board and the waveguide. The apparatus further includes a radiating structure disposed on the circuit board. The radiating structure includes an electric field coupling component configured to an electric field between the circuit board and the coupling port and a magnetic field coupling component configured to couple a magnetic field between the circuit board and the coupling port.