161Group III-Nitride Microwave Monolithically Integrated Circuits
The development of broadband amplier based on GaN HEMTs from 30 to
4000MHz (i.e., more than 2 decades) is described in literature [100]. Feedback
and distributed amplier concepts are used. A feedback concept provides
42 dB gain with ± 1.75 dB atness and 32 dBm of output power. C- to Ku-band
ultra-broadband GaN MMIC amplier with 20 W output power is given in the
work of Masuda etal.[101] for the bandwidth of 6–18 GHz with a power gain of
9.6 dB. Arelativebandwidth of more than 115% is reached. The circuit dimen-
sion is 4.8 × 4 mm
2
. A reactive circuit concept is used for the range 6–18 GHz, as
it is argued that the output power of a distributed amplier is lower in th ...