H-Bridge Class-D Power Amplifiers for Digital Pulse Modulation Transmitters

This paper presents an H-bridge class-D power amplifier for digital pulse modulation transmitters. For the proposed class-D amplifier, the drivers of the pull-up and pulldown devices were separated to minimize power loss associated with the shoot-through currents. The amplifier can be driven by binary digital signals generated by a delta-sigma modulator directly. The H-bridge class-D power amplifier system was tested with CDMA IS-95 signals at 800 MHz. The drain efficiency of 31% was achieved with output power of 15 dBm and an ACPR of -43 dBc.