Impact of a half-space interface on the wireless link between tiny sensor nodes

The power budget of a wireless link between two electrically small sensor nodes located close to an interface between two media is studied. The model includes both the propagation channel losses and input impedance of the radio frequency antennas. It is shown that a highly inductive half-space significantly enhances the received power due to the contribution of the surface wave while not resulting in considerable mismatch losses between the antennas and electronics. Hence, such a half-space improves the link gain, which may compensate the limited energy available for transmission from electrically and physically small nodes.