High-Performance CMOS Tunable Differential Active Inductor for RF applications

Design of a CMOS compact tunable differential active inductor (DAI) suitable to low-cost and multi-standard systems is presented. The structure uses only active components, based on the Gyrator-C topology approach with two cross-coupled pairs and an additive feedback resistance to enhance the quality factor (Q). The proposed DAI, implemented in 130 nm CMOS process, achieves a Self-Resonance Frequency (SRF) from few Megahertz to 3.3 GHz. As well, it demonstrates a Q ≈ 388 at 2.31GHz, while the achieved inductance tuning range varies from 33 nH to 98 nH. The circuit consumes 7.28 mW from 1.2 V supply and occupies a small area of only (19×45) um2, Noise, linearity and sensitivity of the proposed DAI to process and mismatch variations are also studied in the paper.