一种新型宽带微带巴伦的设计论文.pdf

四川大学硕士学位论文一种新型宽带微带巴伦的设计无线电物理专业研究生郭福强指导教师陈星副教授摘要巴伦(balanced tounbalanced transformer,Balun)是平衡非平衡转换器的英文翻译,在微波平衡混频器、倍频器、推挽放大器和天线等设备中得到广泛应用。在天线领域中,巴伦可以实现某些天线馈电的不平衡到平衡的转换。随着当今通讯技术的发展,通讯容量的不断扩大,要求天线在更宽的频带内工作, 因此,对巴伦的工作频带要求越来越宽。,宽频带微带巴伦的研究已经成为当今的一个热门课题。本文结合有限元(finite element method,FEM)算法的理论分析,研究并设计了一类宽频带微带巴伦。本论文首次应用接地共面波导(Coplanar Waveguide Ground,CPWG)和耦合微带线(Coupled StripLine,CSL)设计了一种新型的宽频带微带巴伦, 该类型微带巴伦可以在低相对介电常数的介质板上制作,具有结构紧凑,成本低廉,制作简单的特点。采用上述微带巴伦结构,设计和制作了一个50fl非平衡到501'1平衡馈电转换的微带巴伦,通过基于有限元的数值仿真计算和采用网络分析仪器的实际S参数测试,证明该微带巴伦具各优异的超宽带特性, ,测试得到的馈电端口反射系数(S。。)低于一10dB,插入损耗小于3dB。该微带巴伦的工作频带(-)远高于传统巴伦的带宽,也高于绝大多数现有文献设计的宽带微带巴伦。在加入一段切比雪夫阻抗变换段后,设计和制作了一个50fl非平衡到作频带损耗低] 四川大学硕士学位论文 Design of aNovelWideband Microstrip Balun Major:Radio Physics Graduate Student:Guo Fuqiang Advisor:Associate Xing Abstract Balun(balanced tounbalanced transformer,Balun)iS theabbreviation of thebalanced tounbalanced transformer and has already been widely used in many fields such as balanced mixers。frequency multipliers,push-pull amplifiers and antenna an antenna system,a balun will transform all unbalanced feeding signal to a balanced the development of munication technology,antennas are required towork in awider andwider frequency band,which lead tobaluns are also required to have wider and wider to itsadvantages of wideband and easy to be fabricated,the microstrip balun es a hot research topic thispaper,a kind ofnew wideband microstrip balun ispresented and analyzed. The new wideband microstrip balun proposed inthispaper isthefirst balun thatadopts twotransmission lines,CoplanarWaveguideGround(CPWG) and Coupled StripLine(CSL).It can befabricated on asubstrate withlow dielectric constant and possesses severaladvantages,-pacted andeasy tobefabricated. A proposed transforms a50Q unbalanced input tothe50Q balanced output,isdesigned。fabricated and of anumerical simulation