Low-Power and Low-Phase Noise 94-GHz and 107.2-GHz Differential Fundamental Oscillators in 70-nm GaAs pHEMT Technology

This paper presents a family of four W-band (75–110 GHz) differential fundamental oscillators (94/102.7/104.4/107.2 GHz) implemented in a state-of-the-art 70-nm GaAs pHEMT (PP07) featuring 280/360 GHz fT/fmax. The differential oscillator core utilizes cross-coupled transistor pair with an inherently grounded source which is optimized for mm-wave performance. The 94-GHz oscillator delivers a measured phase noise and output power of -115.2 dBc/Hz (at 10-MHz offset) and -6 dBm, respectively, while consuming 66.7 mW. The 107.2-GHz oscillator, with a reduced mesa for enhanced performance, achieves a phase noise of -113.3 dBc/Hz (at 10-MHz offset) and an output power of -11.8 dBm while consuming only 38.6 mW, including output buffers. To the best of the authors’ knowledge, these mm-wave oscillators achieve the highest oscillation frequency with low phase noise and low dc power consumption among prior published GaAs pHEMT single-ended and differential fundamental oscillators reported to date.