This paper presents two MMIC broadband high power amplifiers of 4 mm of periphery at the output stage in the frequency band 2-6 GHz. The amplifiers are based on AlGaN/GaN high electron mobility transistor (HEMT) technology on SiC substrate. They have been fabricated in two different european foundries: SELEX Sistemi Integrati and QINETIQ. SELEX has a gate process technology of 0.5μm, and devices of 10x100μm periphery in microstrip technology and QINETIQ has a gate-length of 0.25μm, and devices of 8x125μm in coplanar technology. The coplanar amplifier from QINETIQ has demonstrated an output power of 8W in continuous wave at V ds =20V which confirm model predictions. On the other hand, SELEX microstrip amplifier has a saturation power of 10W CW at V ds =25V and 4 GHz. This amplifier measured on-wafer in pulsed conditions exhibits a maximum power of 17W at V ds =30V.

This work reports on using Fe modulation doped GaN to fabricate AlGaNiGaN HEMTs to avoid high dislocation density and conductive GaN buffer layers, limiting device performance. Structural characterization of these layers consisted on HRXRD, PL measurements, obtaining information about polarization fields, strain and charge densities. Moreover, Schottky diodes and Ushaped transistors were fabricated at ISOM with 1.3 and 0.3 pm gate lengths. Maximum saturation currents and trasconductances were above 1.2 A i m and 290 mS/mm, respectively. Moreover, the effect of a AIN spacer led to higher electron density and mobility that in reference samples with higher AI content.

This paper describes and evaluates two MMIC broadband high power amplifiers in the frequency band 2-6 GHz in microstrip technology. These amplifiers have scalable output-stage periphery of 4 and 8 mm. The amplifiers are based on 1 mm AlGaN/GaN high electron mobility transistor (HEMT) technology on SiC substrate. They were fabricated in the European foundry SELEX Sistemi Integrati, which has a gate process technology of 0.5 μm. The 4 mm amplifier has exhibited an output power of 15 W and the 8 mm of 28 W at Vds=25 V in pulsed conditions. The best power performance in continuous wave are 10.5 W and 15 W for 4 mm and 8 mm, respectively. Better than 20% PAE over the 2-6 GHz frequency range is achieved in CW.