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

This paper presents an MMIC V-band oscillator employing an on-chip substrate integrated waveguide (SIW) resonator in 0.12-µm GaN HEMT technology. The proposed design adopts an inductor-terminated common-gate topology with a high-Q SIW resonator connected at the source node, where a rectangular cavity resonator is implemented using two metal layers and high-density vias to emulate waveguide boundaries on the chip (cavity size = 1.2mm × 1.3mm), achieving loaded and unloaded Q factors of 70.9 and 146, respectively. Under a drain voltage of only 6V (PDC of 110 mW), the measured results demonstrate an oscillation frequency of 58.6 GHz with a peak output power of 10.1 dBm. The phase noise is -94.3 and -126.5 dBc/Hz at 1 and 10 MHz offset (corresponding FoMs are -169.1 and -181.2 dBc/Hz), respectively. The obtained results are among the best compared to published V-band MMIC oscillators in advanced GaN HEMT technology. To the best of our knowledge, this work is the first reported monolithic GaN oscillator with the SIW resonator.