Design and analysis of UWB band pass filter

To realize a band pass filter (BPF) in ultra-wide band (UWB) communications, a device using a ring resonator with a stub is investigated. A new proposal is made to control the frequency of the attenuation poles using both the ring and the stub impedance. A five stage wide-band BPF is fabricated in this manner. Its center frequency and bandwidth are calculated based on the ring resonator model. The circuit conditions for obtaining two attenuation poles at either side of the pass band are given, together with a method for controlling them.