Parallel push-pull amplifier using complementary device

Abstract

A parallel push-pull amplifier using a complementary device, which basically operates for a B or AB-level amplification while having a common source configuration, thereby being capable of amplifying the full wave of an input signal without any distortion while obtaining a high gain at a radio frequency. The complementary device consists of an active element for amplifying a half wave of an input signal and a complementary active element for amplifying the other half wave of the input signal. The complementary active element has a duality with respect to the active element. The amplifier also includes bias circuits adapted to set respective operating points of the active and complementary active elements. Where the active and complementary active elements constitute a CMOS device, they are connected together in the form of a push-pull connection using a common source type configuration. Where the active and complementary active elements constitute a BJT, they are connected together using a common emitter configuration. This amplifier takes only the advantages of both the existing -source follower configuration and common source configuration while eliminating the disadvantages of those configurations, thereby achieving a high efficiency and a high linearity. Accordingly, it is possible to provide a power amplifier capable of obtaining a sufficient power gain even at a radio frequency.