In modern multi - standard communication systems, multi - band shared - aperture antenna arrays offer an efficient solution for aperture reuse. By integrating multiple antennas that operate at different frequency bands, these arrays can substantially boost system capacity and optimize spectrum utilization. However, in a compact layout, the occlusion effect among antenna elements functioning at various frequency bands can cause a decline in the radiation performance of high - frequency elements. This may manifest as pattern distortion and a reduction in gain. Consequently, effectively restoring the impaired radiation characteristics, without significantly increasing the array's size and profile height, has emerged as a crucial technical hurdle in the widespread practical application of shared - aperture antennas. To tackle this problem, researchers have put forward a range of solutions. For instance, a compact tri - band shared - aperture base station antenna array has been developed by incorporating broadband bandstop frequency selective surfaces (FSS) and electromagnetic transparent antennas. Another approach involves using a dual - band fusion method with low - pass partial reflection surfaces (LPPRS) to restore the performance of high - frequency antennas while leaving the performance of low - frequency antennas unaffected. Additionally, low - scattering radiation elements have been designed. These elements utilize split - ring resonators to generate resonance at high frequencies, thereby mitigating the occlusion effect on other high - frequency radiation elements. These methods effectively deal with the coupling and occlusion issues in shared - aperture antennas, thus facilitating the practical application of shared - aperture antenna technology.