一种新型超宽带小型化U型微带滤波器

Novel Compact Microstrip U-Shape Ultra-Wide-Band ( UWB) Filter

提出了一种新型超宽带(UWB)小型化微带滤波器。这种结构采用多个短路支节并联于主传输线上,短路支节长度为四分之一波长。采用一种新型等效电路对其进行分析、模拟,其中的主传输线、并联支节线以及T型结、拐角、接地孔等不连续处均等效为相应的电路元件,并结合适当的U型电路变形。通过精确建模、仿真,使这种新型结构的滤波器具有更小的体积和更宽的通带。采用0.762 mm厚RT Duriod 6002板材实际制作一个通带为3～21 GHz的超宽带微带滤波器,尺寸为12 mm×21 mm×0.762 mm。该滤波器不仅体积小,且性能优良,其带内损耗小于2.1 dB,回波损耗优于-8.2 dB。实做通带2.96～21.01 GHz,带宽达150.6%,与仿真结果较为吻合,可以满足工程应用的需要。

The new pattern with compact size of ultra wideband （UWB） microwave filter was presented. The new filter was generated from several parallel short-circuited stubs with quarter-wavelength from the main transmission line. A new equivalent circuit was introduced with all parasitic effects of elements, such as the main transmission line, short-circuited stubs, T-junction, bend, and other discontinuities in the new UWB filter, and the U-shape transformation was applied to the ndw filter. The U-shape filter has improved size and bandwidth by modeling and emulating accurately. The 3 -21 GHz UWB filter was realized on RT Duroid 6002 with 0. 762 mm of substrate thickness. The final dimension is measured as 12 mm ×21 mm ×0. 762 mm. It is compact, and delivers excellent scattering parameters with the magnitude of the insertion loss, I S21 I is lower than 2. 1 dB and return loss is better than - 8.2 dB. The fractional bandwidth （FBW） is 150. 6% from 2. 96 GHz to 21.01 GHz. The good agreement is achieved between simulation and measurement results and could meet the engineering demand well.