The radiation/receiving front end of active radio frequency (RF) systems such as phased array radars often needs to be equipped with the radome or electromagnetic (EM) window. As the typical structure-function integrated device

it protects systems’ internal structure from the external environment

and ensures EM waves can efficiently transmit in the working frequency band to ensure RF systems normally operate. Due to the need of sufficient stiffness and strength

the permittivity of radomes and EM windows is generally large

which is easy to reduce the wave-transparent performance and increase the insertion phase shift. Therefore

under the background that traditional technologies are gradually difficult to meet practical applications

it is urgent to explore EM anti-reflection (AR) technologies based on the new mechanism to improve the wave-transparent performance of traditional materials in the working bandwidth and angular domain. As two-dimensional metamaterials

metasurfaces have the ability of multi-dimensional EM regulation and conform to EM equipments’ mainstream development trend in geometric properties

which have important application value for EM AR technologies. This paper systematically introduces the research progress of metasurface EM AR technologies

first briefly reviews the typical traditional EM AR technologies

then mainly introduces the mechanism

design ideas and specific design architecture of metasurface EM AR technologies

and analyzes the characteristics of various EM AR metasurfaces

and finally summarizes and prospects the key problems and development trends in the field of EM AR technologies.