An integrated balun for dual-band LC tank VCO in 130nm CMOS/SOI

The feasibility of a switched LC tank for multi-standards applications has been proved. With our balun structure, the MOSFET (and its noise) is isolated at secondary, therefore Q-factor is less decreased and flicker noise doesn't contribute to phase noise. This new structure has lower phase noise than classical bulk tank particularly when switched on. Moreover this new switched tank occupies only one inductor area (290/spl mu/m /spl times/ 190/spl mu/m).