Bandwidth enhancement of substrate integrated waveguide band pass filter for wireless sensor network applications

This paper presents an implementation of new compact substrate integrated waveguide (SIW) band pass filter (BPF) as a candidate for Wireless sensor network (WSN) applications. The proposed filter is working in UWB frequency and is constructed by three cavities. Two adjacent cavities connected with an iris located in the middle of the structure. While the third cavity is glued above as a superposed layer. In order to transfer the energy to the upper cavity, two symmetrical slots are etched in the top metal of the lower layer cavities. The simulation and performance evaluation have been performed by using the full-wave electromagnetic 3D simulator Ansys HFSS. In the same time, the proposed filter maintains low insertion loss approaching 0 dB as well as good matching since the return loss noted is under 15 dB over the pass band. Moreover, a generated transmission zero located under -15 dB close to the pass band with steep cut-off frequency response. Thus, to guarantee higher selectivity. Furthermore, the compact size of this filter make it suitable for easy integration in systems on chip for microwave circuits.