Bandwidth enhancement of multi-stage amplifiers using active feedback

A new topology for wideband multistage amplifiers (MA) is introduced. The proposed method uses active negative feedback in a chain of amplifiers to extend the bandwidth and improve gain-bandwidth product. The topology has several advantages such as having capability of widening bandwidth as the number of stage increases and enhancing bandwidth by several times that of the dominant pole of each stage. To verify the performance of topology, an 8-stage amplifier in 0.35 /spl mu/m CMOS was designed, where more than 2.8 GHz bandwidth and 40 dB gain were obtained from simulations.