An Ultra-Wideband Bandpass Filter With an Embedded Open-Circuited Stub Structure to Improve In-Band Performance

作者：Weng Min Hang^*; Liauh Chihng Tsung; Wu Hung Wei; Vargas Steve Ramrez

来源：IEEE Microwave and Wireless Components Letters, 2009, 19(3): 146-148.

DOI：10.1109/LMWC.2009.2013733

• Bandpass filter (BPF)
• notched band
• open-circuited stub
• ultra-wideband (UWB)

In this letter, we present a compact ultra-wideband bandpass filter (BPF) with a notch band in the BPF performance by using an embedded open-circuited stub structure. The filter mainly consists of conventional stepped impedance resonator (SIR) as the multiple-mode resonator and two enhanced coupled input/output lines. The bandwidth can be analyzed by using the image-parameter method to obtain the proper dimension of the coupled lines and verified by using electromagnetic (EM) simulation. The embedded open-circuited stub structure in the SIR is used to produce a narrow notched band at 5.8 GHz, which its frequency position and bandwidth can be tuned by its physical parameters. The measured 3 dB fractional bandwidth of 113.8% and narrow notched band with 25 dB rejection is achieved. Good agreement between the EM simulation and measurement is obtained.

• 出版日期2009-3