V-Band GaN Power Amplifier MMICs with High Power-Bandwidth and Low Gain Compression for RF Inter-Satellite Links

This paper presents two V-band power amplifiers that are designed and fabricated using Fraunhofer IAF's 0.15-µm gate-length GaN/SiC HEMT technology. Both amplifiers, a unit PA and a balanced PA comprising two of the unit PAs, are four-stage designs that target the upper V-band for wideband inter-satellite links with high output power at low gain compression. When mounted on a test-jig, biased at a de- rated drain voltage and characterized with a CW stimulus, the unit amplifier and balanced amplifier exhibit a linear gain of, respectively, 19.6-21.8 dB and 18.6-21.0 dB, in the band between 57-70 GHz. In the same band, the amplifiers deliver a saturated output power of 31.9-33.4 dBm (1.5-2.2 W) at a PAE of 9.4-14.0% (unit PA) and 33.5-34.9dBm (2.2-3.1 W) at a PAE of 8.6-11.0% (balanced PA). Both amplifiers exhibit good amplitude linearity, with <0.3 dB difference between OP ₂(dB) and P (sat) across the band for the balanced amplifier. To the authors' best knowledge, these results represent the best power-bandwidth performance of published PAs in the V-band.