Integrated-Schottky-Diode GaN HFETs for high-efficiency digital PA MMICs at 2 GHz

This work describes the integration of Schottkydiodes into fast GaN MMIC technology suitable for the realization of switch-mode amplifier core chips for class-S operation at 2 GHz. With the demonstration of this technology, the so-called 3rd-quadrant-issue, which reduces the efficiency in bandpass-Delta-Sigma class-S-type amplifiers, can be diminished on device level. MMIC core chips are demonstrated which provide good PAE under Delta-Sigma operation at 5.2 Gbps.