Reconfigurable RFICs for frequency-agile VCOs in Si-based technology for multi-standard applications

This paper presents novel reconfigurable RFICs for intelligent radio applications. It includes a new fully tunable active inductor (TAI) along with frequency-agile VCOs. The ICs are implemented on both 0.18 /spl mu/m Si-CMOS and 0.18 /spl mu/m SiGe-BiCMOS technologies. The novelty of the TAI lies in the use of a tunable active feedback resistor that results in inductances tunable from 0.1 nH to 15 nH with Q < 50 in C-band. Very wideband reconfigurable VCOs have been implemented using the proposed active inductor, and also with a switched-spiral topology. The VCO tuning ranges are as high as 4 GHz in the C-band. Analysis of the results, taking into account the technologies as well as the circuit topologies, is also presented.