Demonstrator of Class-S Power Amplifier for base stations based on GaN technology

Demonstrator of a class-S power amplifier based on GaN transistors is presented. Input signal is generated externally in simulation tools (ADS, Matlab) based on a 4th order Bandpass Delta-Sigma modulator definition and a FPGA board is used as a signal source. The demonstrator is based on a Current Switching Class D (CSCD) topology. The presented solution offers an output power of at least 37 dBm (dependending on the supply voltage). Module efficiency is 20% (30% drain efficiency respectively) for full scale 3 GPP Delta-Sigma input signal. Center frequency is set to 225 MHz, with the posibility of increase for the purpose of analysis and measurements.