A 6th order wideband active-RC LPF for LTE application

A low power, highly linear active-RC filter is presented. This filter is synthesized from a low pass 6 order Chebyshev RLC ladder, and exhibits a reconfigurable bandwidth (10 MHz, 50 MHz). In order to meet the high cutoff frequency (50 MHz) and strict adjacent channel rejection requirements, a novel operational amplifier based on a new compensation technique is used, which optimizes high frequency filter performance and minimizes current consumption. This filter is fabricated in a 0.18 m CMOS process, the measurement results indicate that the filter provides 10 MHz and 50 MHz selectable bandwidth, and excellent adjacent channel rejection: -15.3 dB at 12.5 MHz with 10 MHz cutoff frequency, -8.3 dB at 60 MHz with 50 MHz cutoff frequency, three times out-band rejection more than 60 dB while the in-band ripple is less than 1 dB.