Spoof surface plasmon polaritons (SSPPs) have been considered as a new-type surface wave transmission line (TL) because of its single line feature. However, it cannot be directly fed by the measured system because the transmission mode of SSPP TLs is totally different from the traditional TLs like microstrip lines. Also, the existing solutions require complicated structures and a big area on the circuit space to complete the transition between the two different propagation modes. Here, we propose an ultracompact and simple transition from the microstrip line to the SSPP single-conductor TL, consisting of a very short section of gradient corrugations and a specially designed flaring ground etched on the bottom side of the SSPP TL. Numerical simulations show a good agreement with the experimental results, showing high transmission efficiency for the proposed transition in a broad relative bandwidth from 4.5 to 11.5 GHz. Moreover, this SSPP feeding prototype is easy to migrate to other single-conductor SSPP devices.

中文翻译：

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从微带线到欺骗表面等离子体激元的宽带和高效紧凑过渡

欺骗表面等离子体激元（SSPPs）因其单线特性而被认为是一种新型的表面波传输线（TL）。但是，由于SSPP TL的传输方式与微带线等传统TL的传输方式完全不同，因此不能由被测系统直接馈电。此外，现有的解决方案需要复杂的结构和较大的电路空间面积来完成两种不同传播模式之间的转换。在这里，我们提出了一种从微带线到 SSPP 单导体 TL 的超紧凑和简单的过渡，由非常短的梯度波纹部分和蚀刻在 SSPP TL 底部的专门设计的扩口接地组成。数值模拟与实验结果吻合良好，显示在从 4.5 到 11.5 GHz 的较宽相对带宽中提议的过渡的高传输效率。此外，这种 SSPP 馈电原型很容易迁移到其他单导体 SSPP 设备。