A compact UWB bandpass filter with a notched band using a multistubs loaded resonator

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• 作者：Ting Zhang ; Fei Xiao ; Jingfu Bao and Xiaohong Tang
• 刊名：International Journal of RF and Microwave Computer-Aided Engineering
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：27
• 期：1
• 全文大小：949K
• ISSN：1099-047X

文摘

A novel multistubs loaded resonator (MSLR) is proposed in this article, which is constructed by several open- and short-circuited stubs. The analysis shows that it is characterized by four resonant modes. Then, the MSLR is applied in the design of a compact ultra-wideband (UWB) bandpass filter. The measured results show that its 3dB bandwidth can cover [3.0, 11.5] GHz, that is, 3 dB fractional bandwidth is 117%, and the return loss within the passband is greater than 15 dB. Especially, the roll-off rate is higher than 33 dB/GHz and more than 40 dB harmonic suppression can be achieved up to 17 GHz. In order to suppress the interference of some undesired narrowband signal such as wireless local-area network (WLAN) radio signal, a notched band is created for the UWB bandpass filter, which is realized by forming one stepped slot on each of the feedlines, respectively. The measured results show that a notched band with 2.01% fractional bandwidth at the center frequency of 5.85 GHz can be achieved and its suppression is about −19 dB.