There is no best amplifier, different amplifiers are used for different purposes, and it depends upon specific requirement to use what type of amplifie

It is defined as the defined as the ratio of the output power to the input power and is usually expressed in decibels (dB). The gain of power amplifier can be calculated using the following formula, \(Gain(dB)=10\times log_{10} (\frac{P_{out}}{P_{in}})\)

Because Class AB offers a decent balance between classes A and B in terms of efficiency and linearity, i.e., 50% and 60%. Because the output signal's amplitude and phase are linearly related to the input signal's amplitude and phase, the class A, B, and AB amplifiers are known as linear amplifiers.

This can be analysed in two ways as Positive half cycle and negative half cycle. For Positive half cycle in input →Negative half cycle is obtained at output For Negative half cycle in input → Positive half cycles is obtained at output

The operating point is raised above the cutoff point due to the tiny bias voltage provided by diodes D1 and D2 in Class AB Power Amplifier.