Design and analysis of differential ring voltage controlled oscillator for wide tuning range and low power applications

Abstract

Summary Voltage‐controlled oscillator (VCO) is the most basic component required for all wireless and communication systems. In this article, a four‐stage differential ring VCO with two control voltages for wide tuning range is proposed. This VCO uses the dual‐delay loop technique for high operation frequency. Also, a low‐VT NMOS transistor is used in series with pull down network of the proposed VCO delay cell to achieve low frequencies. Prelayout simulation of the proposed VCO is performed in 65‐nm TSMC CMOS technology in Cadence software under 1.2‐V supply voltage. The tuning range of the proposed VCO varies from 1 MHz to 13.8 GHz and has been improved by 19.77% compared to other works. The power consumption of this low power VCO is between 29.3 μW to 1.715 mW. The phase noise of the proposed circuit is −82.3 dBc/Hz at 1 MHz offset frequency and −106.9 dBc/Hz at 10 MHz offset frequency from 5.161 GHz center frequency, while its area is 102.457 μm2. This design demonstrates other benefits in low power consumption and area compared with other ring oscillators.

A low‐power delay stage ring VCO based on wrap‐gate CNTFET technology for X‐band satellite communication applications

“…Moreover, because of the inherent limitation of the transconductance at deep subnanometric dimensions, the GAA-CNTFETbased VCO shows a limited tuning range compared to the Chahine et al, Salem et al, and Askari and Saneei works that are implemented via commercialized technologies. 32,33,41 Based on the results and the undiscovered potentials of GAA-CNTFET transistors in deep nanometric dimensions, we believe that by further enhancement of fabrication techniques in representing high-performance ultraminiature CNTFET transistors in the future, the proposed GAA-CNTFET-based ring VCO can be considered as a promising platform for X-band satellite communication applications.…”

“…Therefore, we envision that the proposed VCO would have better phase noise characteristics in the actual conditions. Moreover, because of the inherent limitation of the transconductance at deep subnanometric dimensions, the GAA‐CNTFET‐based VCO shows a limited tuning range compared to the Chahine et al, Salem et al, and Askari and Saneei works that are implemented via commercialized technologies 32,33,41 …”

“…To gain a full control over the frequency range, in 2019, Askari and Saneei presented a delay stage VCO in 65 nm standard CMOS technology. This VCO benefited from a dual‐control voltage configuration and showed a 99.99% controllability over the oscillation frequency 41 . However, the VCO of Askari and Saneei suffers from a poor phase noise response (‐82 dBc/Hz) and therefore cannot be utilized for low‐noise applications.…”

“…This VCO benefited from a dual-control voltage configuration and showed a 99.99% controllability over the oscillation frequency. 41 However, the VCO of Askari and Saneei suffers from a poor phase noise response (-82 dBc/Hz) and therefore cannot be utilized for low-noise applications. Walunj et al utilized 32 nm FinFET technology to demonstrate an ultralow-power ring VCO.…”

Design of a 3.2 mW Differential Ring VCO with Wide Tuning-Range using Self Biased Active Inductor Topology in 180 nm CMOS process

“…In the last two decades, VCO design engineers are working to improve all the critical constraints including frequency band, phase-noise, power dissipation, the figure of merit, and occupied layout area while building VCOs. Hence, various differential VCO modeling strategies have already been developed to magnify these critical parameters [8][9][10][11][12][13][14][15][16][17][18]. A VCO with a fully switching differential dual delay stage is reported in [8] to enhance the performance of phasenoise, but it suffers from a low-frequency range.…”