ABSTRACT In this work, we present the analysis and design of a perfect metamaterial absorber (MA) based on the circular cavity with one side open in the terahertz region. This structure consists of a metal plate where one circular cavity with one side open is vertically placed on. Based on the circular-cavity-theory, a formula can be used to calculate the resonant frequency. In terms of normal incidence, the simulated results show that the MA has one resonance point on 6.674 THz, which is consistent with the calculated results. What’s more, we present the distribution of E-field, surface current distribution and power loss density distribution in the cavity, and use the standing wave theory and electric dipole to prove the physical mechanism of the perfect absorption. Finally, an MA based on elliptical cavity with one side open is also studied. These results verify the application of resonant cavities in the field of MA.

中文翻译：

---

基于圆形或椭圆形腔的完美超材料吸收器，一侧在太赫兹区域开放

摘要 在这项工作中，我们提出了基于圆形腔的完美超材料吸收器 (MA) 的分析和设计，其中一侧在太赫兹区域开放。这种结构由一块金属板组成，其中一个一侧开口的圆形空腔垂直放置在金属板上。基于圆腔理论，可以使用一个公式来计算谐振频率。在法向入射方面，模拟结果表明MA在6.674 THz上有一个共振点，这与计算结果一致。更重要的是，我们提出了腔内的电场分布、表面电流分布和功率损耗密度分布，并利用驻波理论和电偶极子证明了完美吸收的物理机制。最后，还研究了基于椭圆腔的一侧开放的 MA。