A new high speed and high efficiency GaN HEMT switching cell for envelope tracking modulators

This paper presents a new high-speed and high-power switching circuit based on GaN HEMTs, well suited for envelope tracking supply modulators. The proposed switching cell operates up to 100MHz switching frequencies and provides output voltages up to 50V with high efficiency. This new topology takes advantage of a minimum number of components for reducing switching power losses. Moreover, this circuit acts like an inverting threshold comparator with rising and falling times in the order of one nanosecond. A theoretical analysis of static operation and a design approach are described and validated with measurements performed on a hybrid demonstration board.