saturated vs linear power amplifier

To design linear power amplifier does one have to just design a saturated power amplifier at high Psat (by burning more current) or is there any other way? Does one select device in a different way in both BJT and FET? Thanks.

Designing a linear power amplifier its a more complex job than just increase the DC bias current.
During the design, parameters as Gain, P1dB, IP3, AM-PM, ACPR (if use digital modulation), Noise Power, etc, should be measured.
All of these parameters can differentiate a linear PA by a saturated PA.
Most of the PA transistors mentioned in the datasheets the maximum linear or saturated output power, which is your criteria selecting the transistor.

But I read in the books that people backoff from psat as per linearity requirement. Is there a writeup somewhere that distinguishes the design of both?

Hi

If u design Linear amp u taking in to the account when u design, at the design step u already taking this backoff and measure all the parametesrs that u need for linearity.
If u r design for saturated amplifier what is important is different parameters like: Psat, Eff, Power Gain etc...