
176 Gallium Nitride (GaN): Physics, Devices, and Technology
Because of their direct impact on the insertion loss in the transmit state, the match-
ing parameters S
11
and S
33
are optimized to be better than
−
15 dB over the full
bandwidth.
As the S
31
compresses under LS-drive for various power levels, in this case up
to 10W, a P
−0.1 dB
better than 1 W is reached at all frequencies; further, a minimum
compression is required for the full bandwidth up to 18 GHz for a power level of
10W. Similar results have been obtained by Campbell and Dumka [147]. The maxi-
mum transmission power transmission in the off-state amounts to
⋅
PW
Z
f
pi
()=
2
Max,of