周期性结构在毫米波波导同轴转换中应用

Application of periodical structure in millimeter waveguide coaxial connecter

波导同轴转换连接器是微波、毫米波通信和测试中非常重要的器件.基于PBG(Photonic Band-Gap)和阶梯阻抗变换结构在导波系统中对电磁波传播性能的影响,探讨和研究了将这2种周期性结构应用在8 mm波导同轴转换连接器的设计中的情况,通过在同轴腔内导体介质支撑垫中布置二维PBG结构抑制同轴部分横向溢散的电磁波,通过在波导腔体内增加阶梯阻抗结构,改善阻抗变换效率,提高波导同轴转换器件的传输性能.仿真和实验证明了这种PBG/阶梯阻抗变换结构在毫米波波段同轴波导转换设计应用中的有效性,改善了系统的性能及稳定性,在不增加通常的调谐器件情况下,在较宽的频带范围内有效降低了驻波比.

Waveguide coaxial connecter has been playing a very important role in microwave ＆ millimeter-wave communications and tests. On the basis of the effects of PBG（photonic band-gap） structure and step impedance conversion structure in transmitting electromagnetic wave system, a novel waveguide coaxial connecter for 8mm has been discussed and studied based on above two structures, the 2D air column structure in dielectric support cushion depress the dissipation of electromagnetic wave in coaxial structure, at the same time, the step impedance conversion structure improve the performance of waveguide to coaxial port, these two conversion structures in designing of 8 mm waveguide coaxial connecter. Simulations and measurement accuracy proved that this structure has the capability of improving the communication performance of millimeter waveguide coaxial connecter and reducing VSWR（voltage standing wave ratio） at a very wide frequency band without additional components used for tuning.