A V-Band GaN Oscillator Using an On-Chip High-Q SIW Resonator With an FoM Up to -181.2 dBc/Hz

This paper presents a V-band MMIC oscillator employing an on-chip SIW resonator in 0.12-µm GaN HEMT technology. The design uses an inductor-terminated common-gate topology, integrating a high-Q rectangular SIW cavity (1.2 mm × 1.3 mm) formed by two metal layers and dense vias to emulate waveguide boundaries with high accuracy. The resonator achieves loaded and unloaded Q factors of 70.9 and 146, enabling stable and low-noise oscillation. With a drain voltage of only 6 V and 110 mW power consumption, the oscillator demonstrates a measured 58.6-GHz oscillation frequency and 10.1-dBm output power. Phase noise reaches –94.3 and –126.5 dBc/Hz at 1- and 10-MHz offsets, corresponding to impressive FoMs of –169.1 and –181.2 dBc/Hz. The achieved performance ranks among the best reported for V-band GaN MMIC oscillators, and this work represents the first monolithic GaN oscillator incorporating an on-chip SIW resonator in the literature.