The triband circular electric–inductive–capacitive (ELC)-based monopole antenna for wireless application is proposed. The proposed structure has a closed ring resonator and an ELC metamaterial resonator, which are connected by a small metal stub. ELC, with its unique negative permeability property, modifies the current direction and creates a new resonance that results in multiband characteristics for the proposed antenna. The fabrication of the proposed antenna is done on an FR4 substrate having the dimension 32 × 36 × 1.6 mm3. The measured results show multiband characteristics at 2.23 GHz, 2.56 GHz, and 4.29 GHz with return loss equal to − 34.21 dB, − 25.83 dB, and − 35.89 dB, respectively. The simulated resonant frequency of the proposed circular ELC is validated with quasi-static analysis, and it could be observed that the simulated and quasi-static analysis results comply with each other. Also, the negative permeability and new resonance of the proposed circular ELC metamaterial resonator are verified using the parameter extraction method. The measured and simulated radiation pattern also displays an excellent uniformity between them. The small size, ease in design, minimal return loss, multiband characteristics, and a considerable gain are the significant features of the proposed work.

中文翻译：

---

一种用于无线应用的装有圆形电-感-电容超材料谐振器的三频单极天线

提出了用于无线应用的基于三频圆形电电感电容 (ELC) 的单极天线。所提出的结构具有一个闭环谐振器和一个 ELC 超材料谐振器，它们通过一个小金属短截线连接。ELC 具有独特的负磁导率特性，可修改电流方向并产生新的谐振，从而为所提议的天线带来多频带特性。所提出的天线的制造是在尺寸为 32 × 36 × 1.6 mm3 的 FR4 基板上完成的。测量结果显示了 2.23 GHz、2.56 GHz 和 4.29 GHz 的多频带特性，回波损耗分别等于 - 34.21 dB、- 25.83 dB 和 - 35.89 dB。所提出的圆形 ELC 的模拟谐振频率通过准静态分析进行验证，并且可以观察到模拟和准静态分析结果相互符合。此外，使用参数提取方法验证了所提出的圆形 ELC 超材料谐振器的负磁导率和新谐振。测量和模拟的辐射图在它们之间也显示出极好的均匀性。小尺寸、易于设计、最小回波损耗、多频带特性和可观的增益是拟议工作的显着特点。