Constructing Metastructures with Broadband Electromagnetic Functionality

Electromagnetic metastructures stand for the artificial structures with a characteristic size smaller than the wavelength, which may efficiently manipulate the states of light. However, their applications are often restricted by the bandwidth of the electromagnetic response of the metastructures. It is therefore essential to reassert the principles in constructing broadband electromagnetic metastructures. Herein, after summarizing the conventional approaches for achieving broadband electromagnetic functionality, some recent developments in realizing broadband electromagnetic response by dispersion compensation, nonresonant effects, and several trade‐off approaches are reviewed, followed by some perspectives for the future development of broadband metamaterials. It is anticipated that broadband metastructures will have even more substantial applications in optoelectronics, energy harvesting, and information technology. Broadband electromagnetic response is often required in the applications of metastructures. It is therefore important to reassess the principles of constructing broadband electromagnetic metastructures. Some recent developments in realizing broadband electromagnetic response by dispersion compensation, nonresonant effects, and some trade‐off approaches are reviewed. Perspectives are given on the development of broadband metastructured materials.