In the classical Doherty implementation the main amplifier is biased in Class B and the auxiliary amplifier is biased in
deep Class C [2]. The main PA is always amplifying; on the other hand, due to the bias point, the auxiliary amplifier only turns on when high output power is needed. The auxiliary amplifier’s purpose is to modulate the load to keep the main amplifierinitshighefficiencyregion.IdeallytheDohertytechnique will produce the classical two peak efficiency response shown in Figure 2.