A 1.8-GHz low-phase-noise CMOS VCO using optimized hollow spiral inductors

Abstract

A completely integrated 1.8-GHz low-phase-noise voltage-controlled oscillator (VCO) has been realized in a standard silicon digital CMOS process. The design relies heavily on the integrated spiral inductors which have been realized with only two metal layers and without etching. The effects of high-frequency magnetic fields and losses in the heavily doped substrate have been simulated and modeled with finite-element analysis. The achieved phase noise is as low as 0116 dBc/Hz at an offset frequency of 600 kHz, at a power consumption of only 6 mW. The VCO is tuned with standard available junction capacitances, resulting in a 250-MHz tuning range.

Microwave Integrated CMOS Oscillators on Silicon-on-Insulator Substrate

“…The oscillator output is connected to a spectrum analyser having an input impedance of 50 Ω. A part of the measurements are presented in These results are comparable with those presented in [9][10][11]. However, it has to be kept in mind that the transistors were not optimized at the time the layout was produced, mainly the p-MOS transistors, due to a fabrication problem in the previous process.…”

Implementation of Low Phase Noise Wide-Band VCO with Digital Switching Capacitors

“…In present fast-growing wireless communications, requires wide bandwidth, low-power and low-cost RF circuits [1]. In Fig.…”

Voltage Controlled Ring Oscillator for Low Phase Noise Application

“…High-speed circuits require on-chip oscillators to generate clocks. In recent years, LC oscillators [4] have been known with good phase noise performance, but their tuning range is relatively small (around 10-20%) and on-chip spiral inductors occupy a lot of chip area. On the other hand, ring oscillators usually have a wide tuning range, occupy less on-chip integration area, which makes them being more widely used than LC oscillators.…”