In this paper, we propose a frequency-reconfigurable antenna structure consisting of a dielectric resonator (DR) topped by a superstrate material. Two metasurfaces (MSs) are placed upon the DR and the superstrate, where these two MSs are utilized to synthesize a localized reduction of the dielectric constant of the DR. By placing switches into one of the MSs, the distribution of dielectric constant of the DR can be switched to one of two predefined distributions, which is equivalent to switching the DR length to two different lengths. Consequently, the frequency response of the proposed structure can be tuned to one of two operating bands. The excited modes inside the proposed antenna were obtained analytically and through simulations. Also, the dielectric constant value of substrates topped by MSs was analyzed. The antenna was fabricated and measured, and good agreement between simulation and measurement was attained. The antenna bandwidths are 7–8.1 GHz (14.7%) and 8.5–9.2 GHz (8%) and the gains are 5.1 and 7.8 dB, in the cases of having switches off and on, respectively.

在本文中，我们提出了一种频率可重构天线结构，该结构由顶部覆有材料的介电谐振器 (DR) 组成。两个超表面 (MS) 放置在 DR 和覆板上，其中这两个 MS 用于合成 DR 介电常数的局部降低。通过在其中一个 MS 中放置开关，可以将 DR 的介电常数分布切换到两个预定义分布之一，这相当于将 DR 长度切换到两个不同的长度。因此，所提出结构的频率响应可以调谐到两个工作频带之一。所提出的天线内部的激发模式是通过分析和模拟获得的。此外，分析了顶部有 MS 的基板的介电常数值。天线制作完成并进行了测量，仿真与测量之间取得了良好的一致性。天线带宽为 7-8.1 GHz (14.7%) 和 8.5-9.2 GHz (8%)，增益分别为 5.1 和 7.8 dB，在开关的情况下。