diff --git a/tech/Antenna.wiki b/tech/Antenna.wiki
index 18b97ee..a040051 100644
--- a/tech/Antenna.wiki
+++ b/tech/Antenna.wiki
@@ -15,4 +15,34 @@ changes dramaticly, and therefore it often doesnt matter what oerientation an
 antenna has when working with signals that propogate often (such as HF, see
 [[frequency_range]]). This phenomenon is called eliptical polarization.
 
+== Feed line ==
 
+A feed line delivers a signal to the antenna. The ratio of voltage to current
+is [[Impedance]]. This is due to the ratio of the physical dimesnions of the
+feed point, and the frequency of the signal. They are said to be in _resonance_
+when the feed point impedance is all resistance with no reactance.
+
+The feed points impredance is heavily affected by nearby conductors and its
+height above ground.
+
+== Gain ==
+
+Gain is concentrating an antenna's radiated signals in a specific direction.
+Gain aids in concentrating the antenna in an intended direction. This is done
+by creating waves that constructivly add in certain directions, and destruvily
+subtract in others.
+
+*Omnidirectional antenna* radiate in all directions, and therefore have an
+equal gain in all directions.
+
+*Beam* or *directed antenna* have gain in a single direction, and are great for
+communicating in a specific direction.
+
+An *isotropic antenna* is a theoretical antenna that has no gain, because it
+radiates equally in all directions. No such antenna exists, and is used for
+reference.
+
+Gain is measured in decibels (dB) and is in reference to something, most often
+an isotropic antenna (abbr. dBi) or with respect to a dipoles peak gain (abbr.
+dBd). The gain is often showns using an azimuthal and elevation diagram,
+showing views from the top and side respecivly.