Frequency-agile CMOS RFICs for multi-mode RF front-end

This paper presents new reconfigurable RFICs for multi-band applications. It includes a new fully tunable active inductor (TAI) and a frequency-agile VCO implemented using the proposed TAL The ICs have been implemented in 0.18μm CMOS technology. The novelty of the TA1 lies in the use of a tunable feedback resistor that results i n inductances tunable from O.lnH to 15nH with Q>50 for 0.5-3GHz. This new reconfigurable TA1 is used to implement a wideband frequency-agile VCO covering several commercial frequency bands for application in a multi-mode RF frontend. As a proof of concept, a wideband TAI-based VCO has been implemented in 0.18μ CMOS technology. The measured VCO shows an 85.7% tuning range from 500MHz to Z.OGHz. Analysis using theoretical expressions for the new active inductor is also presented.