  We present a summary of the basic properties of the radio wave generation,
propagation and reception, with a special attention to the gigahertz bandwidth
region which is of interest for wireless sensor networks. We also present some
measurement results which use the so-called RSSI indicator in order to track
how the field strength varies with position and distance of the transceivers.
We hope the paper may be useful to anyone who looks for a quick review of the
fundamentals of electromagnetic theory with application to antennas.
