Highly Efficient Dual-Switch Hybrid Switching Supply Modulator for Envelope Tracking Power Amplifier

This letter describes a highly efficient dual-switch hybrid switching supply modulator for an envelope tracking power amplifier (PA). The supply modulator has a combined structure of a linear amplifier and a switching amplifier. For an improved efficiency, the switching amplifier employs two buck converters and realizes an adaptive slew rate control of the switching amplifier's current. An implemented envelope tracking PA delivers an efficiency of 39.1% at an output power of 27 dBm for long term evolution signal with 10 MHz channel bandwidth.