An 8W GaN-based H-bridge class-D PA for the 900 MHz band enabling ternary coding

This paper presents an H-bridge class-D power amplifier (PA) for the 900 MHz band based on GaN MMICs. For a classical BPDS modulated signal, a maximum output power of 34.5 dBm with a drain efficiency of 22% is obtained. Using a periodic square-wave input signal, the PA achieves a peak output power of 39 dBm and maximum drain efficiency of 48%. Investigating different binary and a ternary coding schemes, up to 30% drain efficiency at 6 dB power back-off is achieved.