Ultra-Wideband Bandpass Filter Using Multilayer Liquid-Crystal-Polymer Technology
Ultra-Wideband Bandpass Filter Using Multilayer Liquid-Crystal-Polymer Technology
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DOI：
10.1109/tmtt.2008.2002228
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发表时间：
2008-08
影响因子：
4.3
通讯作者：
Z. Hao;Jiasheng Hong
中科院分区：
文献类型：
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作者：
Z. Hao;Jiasheng Hong
提出了一种基于准集总元件原型的新型超宽带（UWB）带通滤波器，并采用多层液晶聚合物（LCP）技术实现。在本研究中，我们采用宽边耦合的微带辐射短截线和高阻抗微带线作为准集总元件，以实现紧凑型超宽频带通滤波器。通过引入短路高阻抗微带线作为并联电感，并适当设计准集总元件电容，实现了符合联邦通信委员会（FCC）UWB规范的紧凑型六极点带通滤波器。为了进一步提高滤波器的选择性和宽带性能，本文提出了一种八极点滤波器，它是通过增加两个并联短路的微带短截线，在通带上沿引入一个传输零点来实现的。建议的过滤器使用多层LCP技术制造。这些滤波器的模拟和测量结果之间的良好协议进行了观察。测试结果表明，所设计的六极点滤波器能够满足FCC超宽带系统的要求。所制作的八极点滤波器具有超宽的分数带宽（139%）和良好的阻带抑制水平，在10.57 ~ 18.0GHz范围内，阻带抑制水平大于38.1dB。所提出的滤波器是有吸引力的UWB通信和雷达系统。
Novel ultra-wideband (UWB) bandpass filters are proposed based on quasi-lumped-element prototypes and implemented with multilayer liquid-crystal-polymer (LCP) technology. In this study, the broadside-coupled microstrip radial stubs and high-impedance microstrip lines are adopted as quasi-lumped elements for realizing compact UWB bandpass filters. By introducing a short-circuited high-impedance microstrip line as a shunt inductor and suitably designing quasi-lumped-element capacitors, a compact six-pole bandpass filter is implemented with the Federal Communications Commission (FCC) defined UWB specifications. To further improve the selectivity and wideband performance, an eight-pole filter of this type is developed by adding two shunt short-circuited microstrip stubs, which introduce a transmission zero at the upper passband edge. The proposed filters are fabricated using multilayer LCP technology. Good agreement between simulated and measured results of these filters are observed. The measured results show that the fabricated six-pole filter has good specifications for the FCC-defined UWB system. The fabricated eight-pole filter has an ultra-wide fractional bandwidth (139%) and a good stopband rejection level, which is higher than 38.1 dB from 10.57 to 18.0 GHz. The proposed filters are attractive for UWB communications and radar systems.