On the other hand, in order to improve the linearity of Doherty power amplifier, one of the possible and simplified techniques is Composite Right/Left-Handed Transmission Lines (CRLH-TL) for its character of suppressing the second harmonic of the carrier amplifier
of the Doherty power amplifier.
At this time, the carrier amplifier
will be gradually saturated to keep a high efficiency while the peak amplifier provides the additional power required.
The advantage is that the carrier amplifier
amplifies only the average signal.
A conventional Doherty amplifier is composed of a carrier amplifier
and a peak amplifier.
A Doherty amplifier consists of a carrier amplifier
, a peak amplifier and a power combining network.
The RF performances of the Doherty amplifier-I (a combination of a class B carrier amplifier
and a bias-tuned class C peaking amplifier) have been compared with those of a class B amplifier alone.
The displayed amplifier shown is an 80 W IS-136 compliant PCS single carrier amplifier
operating from a wide range 20 to 30 V DC supply.