This paper proposes a novel multiband antenna using circle and triangle fractals for wireless application. By cutting a triangle slot in the circular monopole, a novel fractal method of the circular nested triangle structure is presented. The above structure is iterated four times, which forms the proposed fractal antenna. The antenna adopts the microstrip feeding method. In order to improve out band rejection and expand bandwidth, a ring resonator is designed on the back of the dielectric plate. The designed antenna covers 1.8 GHz–2.9 GHz applied to Bluetooth, TD-SCDMA, WCDMA, CDMA2000, and LTE33-41, 3.4 GHz–4.6 GHz applied to LTE 42/43 and WiMAX, and 5 GHz–5.6 GHz applied to WLAN. The substrate is FR4 with a dielectric constant of 4.4 and a loss tangent of 0.02. The size of the fabricated antenna is 87.5 × 61 × 1.6 mm. The measured pick gain achieves 2.98 dBi, 2.58 dBi, and 3.34 dBi at 2.6 GHz, 3.8 GHz, and 5.3 GHz, respectively. The measurement and simulation results are in good agreement, which verifies the rationality of the design.

中文翻译：

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一种用于无线应用的新型多频带分形天线

本文提出了一种用于无线应用的使用圆形和三角形分形的新型多频带天线。通过在圆形单极子上切出三角形槽，提出了一种新的圆形嵌套三角形结构的分形方法。上述结构迭代四次，形成了所提出的分形天线。天线采用微带馈电方式。为了提高带外抑制和扩展带宽，在介质板的背面设计了环形谐振器。设计的天线覆盖1.8 GHz-2.9 GHz适用于蓝牙、TD-SCDMA、WCDMA、CDMA2000和LTE33-41，3.4 GHz-4.6 GHz适用于LTE 42/43和WiMAX，以及5 GHz-5.6 GHz适用于WLAN。基板为FR4，介电常数为4.4，损耗角正切为0.02。制成的天线尺寸为 87.5 × 61 × 1.6 mm。测得的拾取增益在 2.6 GHz、3.8 GHz 和 5.3 GHz 下分别达到 2.98 dBi、2.58 dBi 和 3.34 dBi。测量结果与仿真结果吻合较好，验证了设计的合理性。