Low-Voltage Differentiator for VHF Filtering

In this paper a G _m -C resonator circuit is proposed which is based on a new current-mode differentiating concept, compatible with low voltage and very high frequency operation.A prototype 4th-order 200 MHz band pass filter has been fabricated using a 0.8 m CMOS process and shows a side-band rejection lower than –80 dB. This response confirms the feasibility of the proposed resonator in very-high frequency applications such as IF band pass sections of RF front-end circuits. The filter consumes less than 5.5 mW from a 2.7 V supply and the measured dynamic range is 57 dB at IM3 of 0.5%, where the active area is 0.12 mm².