Research on the electromagnetic characteristics of metasurfaces based on air dielectric substrates

Abstract

Electromagnetic metasurfaces can achieve effective control of electromagnetic waves and achieve effects such as blocking, enhancing, reflecting, transmitting, or deflecting electromagnetic waves, possessing electromagnetic properties that go beyond traditional materials. Existing research indicates that the dielectric substrate of metasurfaces has a significant impact on their electromagnetic properties. Increasing the substrate thickness will be beneficial for expanding the impedance bandwidth of the metasurface, and changes in dielectric constant will also have some impact on the operating frequency and bandwidth of the metasurface. A metasurface based on an air substrate was proposed through the research of dielectric materials. In addition, an ultrawideband, miniaturized, and high-gain metasurface antenna based on an air substrate is designed. The overall size of the designed antenna is 0.5λL × 0.5λL (where λL represents the wavelength at the lowest working frequency in free space). The measured results indicate that the proposed antenna exhibits a −10 dB impedance bandwidth of 74.3% (2.53–5.52 GHz) and a peak boresight gain of 10.1 dBi.