A Q-enhancement technique based on active com- vcci pensation of monolithic inductors for parallel resonant LC tanks Cp is presented. Narrowband Q-enhancement is achieved using a h, M3 I -I M6 gyrator to produce a negative inductance and negative resistance. Ztank Lp ZTAI L2 The circuit is optimized for low-power operation and allows M8 __ DC voltage control of Q-enhancement. A simulated two-stage M2 M9 capacitively-coupled Butterworth filter in 0.18,um CMOS con- M4
Kenneth A. Townsend, James W. Haslett