UWB Band Pass Filter with WLAN notch

In this paper, UWB technology operating in broad frequency range of 3.1-10.6 GHz has shown great achievement for highspeed wireless communications. to satisfy the UWB system requirements, a band pass filter with a broad pass band width, low insertion loss, and high stop-band suppression. UWB band-pass filter (BPF) with wireless local area network (WLAN) notch at 5.8 GHz and 3-dB fractional bandwidth of 108% using a microstrip structure is presented. Initially a two transmission pole UWB band pass filter in the frequency range 3.1-10.6 GHz is achieved by design a parallel-coupled microstrip line with defective ground plane structure using GML 1000 substrate with specification: dielectric constant 3.2 and thickness 0.762 mm at centre frequency 6.85 GHz. In this structure a ë/4 open circuited stub is introduced to achieve the notch at 5.8 GHz to avoid the interference with WLAN frequency with lies the desired UWB band. The design structure was simulated on electromagnetic circuit simulation software and fabricated by microwave integrated circuit technique. The measured VNA results show the close agreement with simulated results. Index Terms — UWB (ultra wide band), BPF (band pass filter), PCML (parallel coupled microstrip line), WLAN (wire less local area network).MIC (microwave integrated circuit), SIR (step impedance resonator), DGS (defective ground structure)