Active feedback amplifier approach for microwave filter

In this paper, a novel microwave active filter based on the traditional lumped and transversal filter architecture is presented. This new filter adopts an active feedback amplifier topology in order to provide higher selectivity. Also, an alternative filter synthesis is derived from this topology for the conventional lumped and transversal filter. In order to demonstrate its usefulness, a L-band active filter is designed at GSM1800 center frequency 1.8 GHz with 30 MHz 3 dB bandwidth and evaluated in terms of computer simulation. These simulated results demonstrate that the proposed filter architecture has superior performance when compared with the traditional lumped and transversal filter.