E-Band 85-mW Oscillator and 1.3-W Amplifier ICs Using 0.12µm GaN HEMTs for Millimeter-Wave Transceivers

This paper presents two oscillators (OSCs) and a high power amplifier (PA) for millimeter-wave transceivers. The circuits were designed with a grounded coplanar waveguide (GCPW) and 0.12-μm GaN HEMT technology. One OSC, which was based on a simple series source feedback topology, oscillated at a frequency of 74.5 GHz with an output power of 2.2 mW (3.38 dBm). This oscillation frequency was the highest ever reported for GaN HEMT OSCs. Another OSC with a buffer delivered a record power of 85 mW (19.28 dBm) at 70.75 GHz. In addition, a single-chip PA with a 3-stage common source scheme delivered an output power of 1.3 W (31.13 dBm) at 75 GHz with a CW source module. The 3-dB bandwidth of the PA was 13 GHz from 67 to 80 GHz. The performance of these devices is sufficient for use in E-band fixed wireless access systems and automotive radar systems. The results demonstrate that the GaN HEMTs represent a feasible means of addressing the stringent demands imposed by various millimeter-wave applications.