Current Shared Cascade Structure for the Driver Stages of Switching Mode RF Power Amplifiers

In this work, we propose a current shared cascade (CSC) structure for the driver stages of switching mode RF power amplifiers (PAs); this CSC is designed using a differential structure. The CSC structure is composed of a first driver stage stacked on top of a second driver stage. The first and second driver stages share a dc current and the effective supply voltages of each driver stage become approximately half the value of the supply voltage of the power stage. The CSC structure enhances the power efficiency because no additional regulator, usually required for the supply voltage of the driver stages, is necessary. We designed the PA to prove the feasibility of the proposed CSC structure. From the measured results, we successfully verify the feasibility of the proposed topology.