One of the most annoying problems of satellites, is power
availability.

Mainly in trasponder operations PA's consume vast amounts 
of power.

The use of modern very high efficiency RF amplifiers have
been often limited because they are best fit for constant 
envelope signals.

Also,due to the difficulty of heat sinking in space aether
we must face the need to reduce at minimum the generation 
of heat.

The problem becomes pesky in smaller satellites, where the
room for solar panels is (very) limited.

Various techniques have been developed for terrestrial use
(where the actual goal was reduce the electricity bill in 
high power transmitters) like Chirieix and Doherty, using 
splitters and combiners to fed combinations of linear and
non-liner power amps.

Sometimes is possible, like into digital polar exciters to
directly generate a separate magnitude / phase signal from
baseband and manipulate properly to obtain a linear output 

But in satellite trasponders the input is a signal already
modulated.

A method to decompose a SSB signal was first described by 
Kahn (1952): EER, or Envelope Elimination and Restoration

I am working on a system useful for small satellites, that
combines a simple envelope / phase detector and a class-E
or class-D PA.