At that power level you may not find anything suitable,
most mW-range radios in low cell band are long since
integrated. 100mW (+20dBm) is well within the working
range of a stack-of-two 3.3V RFSOI technology's basic
NMOS (which should hang just fine at 900MHz) and
many have some sort of extended drain / LDMOS option
(like TowerJazz CA18 180nm has 5V/12V devices on many
sub-flows, JI or SOI, aimed at precisely such applications
with only the DGO and X/Y layout rules being different
from the core flow).
At mW levels you are really talking small signal and you
have numerous other options such as JFET/MESFETs in
silicon, GaN, GaAs, SiGe discrete HBTs and so on. You
are not really looking for a power device and maybe this
is confusing / unduly constraining your search.