your transmitter I would suggest you start by fitting an
external SMA socket which means you can screw onto it
a whole raft of different commercially available third party
antennas offering a wide range of claimed dB ‘boosts’.
There are so many antenna mods you can do to improve
range that if you research it there's practically no limit to
them, hell you can even fit a wifi booster to it to increase
the (wattage) output of the controller if you were so
inclined.
A ‘simplified’ bit of the theory behind antenna types
and dB gain.
Antenna design depends on what they are to be used for.
They are generally 'tuned' to a broader frequency range
than needed, for economic and practical reasons. For
instance while we say this is a 2.4GHz control system it is
not exactly 2.4GHz, it could be 2.35 or 2.45GHZ
depending on what channel you are using and so if it is
calibrated to one end of the spectrum and you change
channel it would mean a somewhat reduced range.
Focusing in on a specific frequency also requires more
precise engineering, driving up cost.
Then we have signal 'pattern'.
To liken the transmission from your controller to a light
source is a simple way of describing it.
