毫米波双工器的研究

【作者】 刘烨；

【导师】 樊勇；

【作者基本信息】 电子科技大学 ， 电磁场与微波技术， 2002， 硕士

【摘要】 双工器是电子系统中的常用部件。本文采用严格的场理论方法分析、优化了Ka波段波导H面T结双工器。该双工器由两个部分组成，即正面金属膜片滤波器和波导H面T结。本文首先采用模式匹配法分析了矩形波导中正面有限厚度金属膜片的不连续性及不连续处高次模的耦合作用，并结合遗传算法和单纯形法完成了正面滤波器的优化设计，计算结果与文献吻合较好。在H面T结毫米波双工器中，波导T结的不连续性通过在T结处引入金属膜片的方法来进行补偿，金属膜片的宽度及其插入波导宽边的深度通过有限元软件优化得到。从数值仿真的结果可以看到，在较宽的频带范围内波导T结可以实现良好的匹配。E面带通滤波器和匹配波导T结的散射矩阵级联后得到整个H面双工器的S参数矩阵，同时考虑双工器中两个带通滤波器与T结的相对位置，完成了毫米波H面T结双工器的优化。 采用本文方法研制的毫米波E面金属膜片滤波器，中心频率36.95GHz，1dB带宽465MHz，带内插损0.98dB；中心频率38.463GHz，1dB带宽495MHz，带内插损0.49dB。H面T结毫米波双工器，通带中心频率为37GHz，38.6GHz，带内插损分别为2.17dB和2.44dB，带外抑制大于60dB。更多还原

【Abstract】 A rigorous field theory analyse of one kind of rectangular waveguide H-plane diplexer is described. E-plane band-pass filter and waveguide H-plane T-junction are the most important parts of the diplexer. Since equivalent-circuit method can bring more error, we use mode-match method and make the computation program for the optimization of the E-plane metal-insert filter. The immediate higher order mode coupling between the discontinuities, which reduces the stop-band attenuation for higher frequencies and the influence of the finite thickness of the metal inserts, which influences pass-band ripple behavior and mid-band frequency are taken into account in the mode-match method. The computation result fits the data in literature well. The discontinuity of T-junction can be compensated by an inserted metal iris, the broadness and insert deepness of the iris can be achieved by optimization using FEM software. From the simulation result we can see that the waveguide T-junction achieves good matching in wide frequency band. The S-parameters of the H-plane diplexer can be deduced by combing the scatter matrix of E-plane band-pass filters and T-junction. The distances between the filters and T-junction are also optimized.To realize the design target, the efficiency optimization methods are necessary. we use genetic algorithm and simplex method in this article. The theory is verified by measured results for Ka-band E-plane filters and diplexers. The measured insertion loss of the E-plane filter in the passbands is about 0.98dB at 37GHz and 0.49dB at 38.5GHz, and the insertion losses are 2.17dB in the 36.75 to 37.25GHz channel and 2.44dB in the 38.25 to 38.75GHz channel of the Ka-band diplexer.更多还原