Design and application of CMOS active inductor in bandpass filter and VCO for reconfigurable RF front-end

• Published in: Integration (Amsterdam) 2022-01, Vol.82, p.115-126
• Main Authors: Nediyara Suresh, Lakshmi, Manickam, Bhaskar
• Format: Article
• Language: English
• Subjects: Active inductor; Bandpass filter; Gyrator-C; Oscillator; Transconductor; Tuning range
• ISSN: 0167-9260; 1872-7522
• DOI: 10.1016/j.vlsi.2021.09.003

This paper presents the design of gyrator-C active inductor. Current reuse technique reduces the noise of transconductor in gyrator. Bandpass filter and voltage-controlled oscillator (VCO) are designed based on the proposed active inductor. Post-layout simulations and PVT analysis are carried out using 180 nm RFCMOS technology at 1.8 V supply voltage. Bandpass filter with center frequency 2.45 GHz attains a noise figure of 6 dB. VCO with a tuning range of 1.5 GHz–2.8 GHz attains a phase noise of −99.86 dBc/Hz. The active area occupied by bandpass filter and VCO are 150 μm × 150 μm and 145 μm × 145 μm respectively. •Current reuse technique is used to realize the negative transconductor in gyrator-C to reduce the noise contribution.•An additional design freedom to tune self-resonant frequency and Q factor of the active inductor an active resistor is used.•A bandpass filter with tuning range 1.6 GHz-2.9 GHz is designed based on the proposed active inductor that occupies less area.•VCO is designed based on the proposed active inductor with a tuning range and phase noise on a par existing designs.