Compact highly selective passive notch filter for 3.1–5 GHz UWB receiver system

This paper deals with the design of highly selective passive notch filter working at 2.4 GHz for 3.1-5 GHz UWB receiver system. The proposed filter aims to enable IEEE 802.11 b/g and UWB standard coexistence in the same terminal device. The filter topology is composed of two paths: the first path contains an all-pass function while the second path contains a band-pass one. By this way, the signal is divided at the circuit input and is combined at its output forming a notch response that exhibits a high rejection at the center frequency of the band-pass filter function. Experimental prototype implemented on Rogers4003 multilayer substrate is built in order to show the benefit of this concept design.