A programmable active-RC complex filter for wireless communications

A programmable active-RC complex filter synthesized from Tow-Thomas Low-Pass prototype is proposed in this paper. The filter features tunable Intermediate Frequency (f IF ), and can be programmed by the external. In addition a tunable damping structure allows to guarantee a minimum image rejection for any value of the tunable range. The filter is implemented in a 0.18µm CMOS technology, consumes 0.36mW and its response ranges from 40kHz to 100kHz (5kHz per step), the minimum image rejection is 62dB. The maximum in-band integrated output noise is 132µV rms , while an in-band IM3 of 20dBc is obtained with v in =140mV rms .