一种新型超宽带微带巴伦的设计

Design of a Novel Ultra Wideband Microstrip Balun

根据接地共面波导和耦合微带线设计了一类新型超宽带微带巴伦(平衡/非平衡转换器)。与传统基于共面波导和共面带状线的微带巴伦相比,该新型微带巴伦采用低介电常数介质基板制作,结构紧凑、成本低廉。设计和制作了一个50Ω非平衡到50Ω平衡馈电转换的微带巴伦,通过有限元的数值仿真和网络分析仪测试,证明了该超宽带微带巴伦具备优异的超宽带特性,从0.1GHz到12.6GHz的频率范围,测试得到的馈电端口反射系数低于-10dB,插入损耗小于3dB。

A novel ultra wideband microstrip balun （balanced to unbalanced transformer） based on Coplanar Waveguide Ground （CPWG） and Coupled Strip Line （CSL） is introduced.In comparison with one kind of traditional microstrip baluns, which consists of coplanar waveguide and coplanar strip line, the proposed balun has several advantages such as low-cost, compacted and easy to be fabricated, because it can be fabricated on a substrate with low dielectric constant and it has simple structure without a complex slot. As an example, a balun, which can carry out the transformation from the 50Ω unbalanced to the 50Ω balanced mode, is designed, fabricated and tested. Results of a numerical simulation based on Finite Element Method （FEM） and a measurement using a network analyzer show this balun possesses quite promising ultra wideband properties. In a very large frequency band ranging from 0.1GHz up to 12.6GHz, its return loss and insertion loss are lower than -10dB and 3dB respectively.