A device is provided that includes a first waveguide configured to guide propagation of RF waves inside the first waveguide. A first side of the first waveguide is configured to emit an evanescent field associated with the propagation of the RF waves inside the first waveguide. The device also includes a second waveguide having a second side positioned within a predetermined distance to the first side of the first waveguide. The second waveguide is configured to guide propagation, inside the second waveguide, of induced RF waves associated with the evanescent field from the first waveguide. The device also includes a first probe coupled to the first waveguide and configured to emit the RF waves for propagation inside the first waveguide. The device also includes a second probe coupled to the second waveguide and configured to receive induced RF waves propagating inside the second waveguide.