Power amplifiers deliver a specific amount of AC power to a load. They are used in audio frequency and radio frequency applications. There are many different types of power amplifiers. Examples include RF power amplifiers, high power amplifiers, audio power amplifiers, power acoustic amplifiers, microwave amplifiers, and MOSFET power amplifiers. An RF power amplifier is used amplify radio frequency (RF) transmissions. A high power amplifier is used to amplify high power transmissions. An audio power amplifier or a power acoustic amplifier can be used to amplify audio transmissions. A microwave amplifier or MOSFET amplifier may be used for high frequency applications. Other power amplifiers are also commonly available.