A low-noise voltage-controlled ring oscillator in 28-nm FDSOI technology for UWB applications

Abstract

In millimeter wave systems, performance degradation mainly occurs due to high phase noise of voltage-controlled oscillators (VCOs). This paper proposes a low power, low phase noise ring-VCO developed for ultra-wide band applications identified for possible 5G usage. For this purpose, a novel differential symmetrical load delay cell based 3-stage ring oscillator has been introduced to design the ring-VCO. The 28 nm CMOS Fully Depleted Silicon On Insulator (FDSOI) technology is adopted for designing this VCO circuit with 1 V power supply while a new voltage control through the transistor body bias is implemented. The simulated results show that the proposed oscillator works in the tuning range of 29–49 GHz and dissipates 3.75 mW of power. It exhibits a phase noise of −129.2 dBc/Hz at 1 MHz offset from 49 GHz oscillation frequency, and a remarkable Figure of Merit (FoM) of −217.26 dBc/Hz. With similar power supply, the phase noise rises to −93.16 dBc/Hz for a second oscillator involving more of active components exactly 9 delay cells. Further, the impact of the operation temperature variation on the VCO performance is investigated. Results show a drift in the oscillation frequency for a temperature step from 27 °C to 40 °C and a degradation of 3dBc in the phase noise performance.