中文摘要：

基于分支线耦合器小型化和谐波抑制特性的要求,提出了一种小型谐波抑制分支线耦合器的设计方法,通过采用等效传输线理论和分形几何结构进行设计。基于此方法,设计了小型谐波抑制3 d B分支线耦合器,并对其进行了实物制作和测试。测试结果表明,该耦合器不仅实现了77.9%的尺寸缩减,而且具有5次谐波抑制的特性。与传统方法相比,设计方法具有尺寸小、谐波抑制特性好、易于制作和集成等优点,可以在无线通信系统中得到广泛应用。

英文摘要：

Based on a consideration of branch-line coupler miniaturization and harmonic suppression characteristics,the design method of a small-size 3 d B branch-line coupler with harmonic suppression is proposed. The method is based on the equivalent transmission line theory and the fractal geometry structure. By adopting the method,a 3d B branch-line coupler is fabricated and tested. The test results demonstrate that the designed coupler realizes a 77. 9% size reduction and the frequency suppressed band width is up to the fifth harmonic frequency point. Compared with the conventional methods,the method proposed in this paper has the advantages of small size,excellent harmonic suppression and easy production and integration. Therefore,the design method can be widely applied in wireless communication systems.