Pulsed gate bias control of GaN HEMTs to improve pulse-to-pulse stability in radar applications

Julien Delprato (1) , Arnaud Délias (1) , Pierre Medrel (1) , Denis Barataud (1) , Michel Campovecchio (1) , Guillaume Neveux (1) , Audrey Martin (1) , Philippe Bouysse (1) , Jean-Michel Nebus (1) , C Tolant (2) , P Eudeline (2)

1 XLIM-C2S2 - C2S2
2 Thales Air Systems

A significant improvement is demonstrated in the measured pulse-to-pulse stability of an S-band 6 W GaN high electron mobility transistor (HEMT) power amplifier by generating an appropriate pulse of the gate bias and thus a warm-up drain current just before each radio-frequency (RF) pulse of a periodic and coherent radar burst. The amplitude and the width of this gate bias pulse preceding each periodic RF pulse of the burst are experimentally varied to investigate the trade-off between the improvement of pulse-to-pulse stability and the total power-added efficiency. Finally, this technique of synchronised warm-up gate bias pulse demonstrated a 10 dB improvement of measured amplitude pulse-to-pulse stabilities to meet the critical stability requirement below −55 dB for the RF power amplifier.

Domaines: Sciences de l'ingénieur [physics]; Electronique; Sciences de l'ingénieur [physics]; Micro et nanotechnologies/Microélectronique

Julien Delprato, Arnaud Délias, Pierre Medrel, Denis Barataud, Michel Campovecchio, et al.. Pulsed gate bias control of GaN HEMTs to improve pulse-to-pulse stability in radar applications. Electronics Letters, 2015, 51 (13), pp.1023-1025. ⟨10.1049/el.2015.1052⟩. ⟨hal-01286826⟩