Microwave filters with improved stopband based on sub-wavelength resonators
Microwave filters with improved stopband based on sub-wavelength resonators
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DOI：
10.1109/tmtt.2005.848828
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发表时间：
2005-06-01
影响因子：
4.3
通讯作者：
Marqués, R
中科院分区：
文献类型：
--
作者：
García-García, J;Martín, F;Marqués, R
本文的主要目的是展示亚波长谐振器的潜力，即开口环谐振器，互补开口环谐振器，以及相关的结构，以抑制微波滤波器中不希望的寄生频带，提高其抑制带宽的一个关键方面。所引用的谐振器的主要相关特性是它们的尺寸（其可以比谐振时的信号波长小得多）和它们的高Q因子。这使我们能够设计阻带结构，具有显着的抑制水平，几个阶段，和小尺寸，可以集成在滤波器的有源区。通过这种方式，没有额外的面积被添加到设备，而感兴趣的通带几乎不变。各种各样的带通滤波器，共面波导和微带技术实现，已设计和制造的作者。这些设备的表征指出，所提出的方法，以提高滤波器的响应与谐波抑制水平在某些情况下接近40 dB的效率。同样重要的是要强调，传统的设计方法的过滤器举行。对于某些配置，谐振器的存在略微降低了感兴趣频率处的相速度。增加的优点是在一定程度上减小了器件尺寸。
The main aim of this paper is to demonstrate the potentiality of sub-wavelength resonators, namely, split-ring resonators, complementary split-ring resonators, and related structures to the suppression of undesired spurious bands in microwave filters, a key aspect to improve their rejection bandwidths. The main relevant characteristics of the cited resonators are their dimensions (which can be much smaller than signal wavelength at resonance) and their high-Q factor. This allows us to design stopband structures with significant rejection levels, few stages, and small dimensions, which can be integrated within the filter active region. By this means, no extra area is added to the device, while the passband of interest is virtually unaltered. A wide variety of bandpass filters, implemented in both coplanar-waveguide and microstrip technologies, have been designed and fabricated by the authors. The characterization of these devices points out the efficiency of the proposed approach to improve filter responses with harmonic rejection levels near 40 dB in some cases. It is also important to highlight that the,conventional design methodology for the filters holds. For certain configurations, the presence of the resonators slightly lowers the phase velocity at the frequencies of interest with. the added advantage, of some level of reduction in device dimensions.