gallium arsenide field-effect transistors, microwave radio frequencies, amplifier circuits

["MIKO" <m-i-k-o@attbi.com>]

Can anyone put THIS into laymen's terms for me?

From: http://whatis.techtarget.com/definition/0,,sid9_gci214515,00.html

gallium arsenide field-effect transistor

Also see metal-oxide semiconductor field-effect transistor.
A gallium arsenide field-effect transistor (GaAsFET) is a specialized type
of field-effect transistor (FET) that is used in amplifier circuits at
very-high, ultra-high, and microwave radio frequencies.? This spans the
electromagnetic radiation spectrum from approximately 30 MHz up to the
infrared band.? The GaAsFET is known for its sensitivity, and especially 
for
the fact that it generates very little internal noise.? This is because
gallium arsenide has exceptional carrier mobility.? The electrons and holes
move through the semiconductor material easily and fast.? The GaAsFET is a
depletion-mode device.? This means that it conducts when no voltage is
applied to the control electrode (gate), and when a voltage appears at the
gate, the channel conductivity decreases.
In weak-signal wireless communications and broadcast reception, GaAsFET
devices perform better than most other types of FET. ? Some types of 
GaAsFET
are used as radio-frequency (RF) power amplifiers.? GaAsFETs are employed 
in
space communications, in radio astronomy, and in experiments conducted by
amateur radio operators.