Ka波段宽带谐波抑制定向耦合器

为解决传统分支线定向耦合器带宽较窄，且应用到线性化器等微波元件中时受谐波信号影响较大的问题，提出了一个宽带且带有谐波抑制功能的定向耦合器。该定向耦合器在双支节定向耦合器的基础上增加一个支节，可有效地提高定向耦合器的带宽，同时将其传输线支节替换为低通滤波结构，以实现对高次谐波抑制的作用。仿真结果表明，该定向耦合器的反射系数和隔离度均小于-15 dB，传输损耗小于3.8 dB，波动范围0.5 dB，相位差为90°且与双支节耦合器相比增加1 GHz带宽。满足耦合器的设计指标，可应用到微波元件中，提高微波元件的性能。

Ka-band wideband harmonic-suppression directional coupler

In order to solve the problem that the traditional directional coupler has a narrow bandwidth and is greatly influenced by harmonic signals, this paper presents a broadband directional coupler with the function of harmonic suppression. The directional coupler adds a branch section to double-branch-line directional coupler, thus can effectively improve the bandwidth. While its transmission lines are added with low-pass filter structures, it can filter harmonics well. The experimental results show that the directional coupler reflection coefficient and isolation are less than -15 dB, the transmission loss is more than -3.8 dB, the fluctuation range is 0.5 dB and the phase difference is 90°. It satisfies the design requirement of coupler, and can be applied to microwave components to improve the performance.