In this letter, a new compact filtering power divider (FPD) on the square substrate integrated waveguide (SIW) with wideband isolation is proposed. As the isolation network is embedded in a square SIW cavity, good in-band isolation, compact structure, and low insertion loss can be simultaneously attained. The proposed FPD consists of the coplanar waveguide feeding line of Port 1, the capacitor, a resistor, and the square SIW cavity. TE ₁₀₁ , TE ₂₀₁ , and slot-line modes can realize third-order filtering response. Center frequency ( $f_{0}$ ) and bandwidth of the filtering response can be independently adjusted. In order to achieve out-of-band isolation, Port 2/3 is placed in the specific position to suppress the high-order modes according to the electric-field distributions of these modes. Finally, a prototype with in-band return loss of 20 dB across 5.59–6.4 GHz is designed at 5.99 GHz. The bandwidths of isolation higher than 21 dB and upper stopband attenuation higher than 20 dB are extended to $2.79f_{0}$ and $2.83f_{0}$ , respectively.

中文翻译：

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具有宽带隔离的紧凑型方形基板集成波导滤波功率分配器

在这封信中，提出了一种在具有宽带隔离的方形衬底集成波导（SIW）上的新型紧凑型滤波功率分配器（FPD）。由于隔离网络嵌入方形SIW腔中，因此可以同时实现良好的带内隔离，紧凑的结构和低插入损耗。拟议的FPD由端口1的共面波导馈线，电容器，电阻器和方形SIW腔组成。TE ₁₀₁ ，TE ₂₀₁ 和时隙线模式可以实现三阶滤波响应。中心频率（ $ f_ {0} $ ）和滤波响应的带宽可以独立调整。为了实现带外隔离，将端口2/3放置在特定位置以根据这些模式的电场分布抑制高阶模式。最后，在5.99 GHz下设计了一个在5.59–6.4 GHz范围内具有20 dB带内回波损耗的原型。高于21 dB的隔离带宽和高于20 dB的较高阻带衰减被扩展为 $ 2.79f_ {0} $ 和 $ 2.83f_ {0} $ ， 分别。