  The possible existence of axion-like particles could lead to a new type of
long distance communication. In this work, basic antenna concepts are defined
and a Friis-like equation is derived to facilitate long-distance link
calculations. An example calculation is presented showing that communication
over distances of 1000 km or more may be possible for $m_{a}< 3.5$ meV and
$g_{a\gamma \gamma} > 5 \times 10^{- 8} {\text{GeV}}^{- 1}$.
