通过加载枝节,改进了基于CPW-微带过渡结构的超宽带带通滤波器。在微带线的中间采用了一个T型枝节以增强其选择性。该T型枝节能够在通带的上下边缘分别产生两个传输零点(2 GHz 与14 GHz)。此外,通过扇形开路枝节引入一个传输零点,将滤波器的上阻带延伸到了16 GHz。最后,加工并测试了一个滤波器用于验证。测试结果表明:该滤波器能够实现131% (2. 6 GHz ~12. 5 GHz)的相对带宽;同时,实测结果和仿真基本一致。

In this paper, a ultra-wideband (UWB) bandpass filter based on the CPW-microstrip transition structure is improved by loaded-stubs. In order to enhance its selectivity, a T-sharp stub is adopted at the center of microstripe line. This T-sharp stub can generate two transmission zeros at the lower and upper passband edges (2GHz and 14GHz). Besides, the upper stopband of this filter is extended to 16 GHz due to a transmission zero introduced by the fan-shaped open stub. Finally, a prototype of the proposed filter is fabricated and measured for verification. The measured results show that this filter achieves a fractional bandwidth of 131%(2. 6 GHz ~12. 5 GHz), while the measured results are in close agreement with the simulated ones.

TN82

国家自然科学基金资助项目(61271034)