## 1 Introduction  
Metamaterials have attracted a growing amount of attention for their fascinating physical properties [1; 2], which could be utilized in research and practical applications. Currently, wavefront manipulation based on metamaterials has become a hot research area, due to their artificial engineered properties and small sizes. However, wavefront engineering based on multilayered three dimensional metamaterials suffers from many drawbacks [1; 2; 3; 4], such as low efficiency and costly fabrication, restricting its development and application. To overcome these drawbacks, metasurfaces [5; 6; 7], a kind of 2D metamaterial, have been introduced, by arranging an array of periodic and quasi-periodic subwavelength antennas on a planar substrate to generate abrupt phases or amplitudes of the incident wave.  
Based on this concept, many metasurfaces have been proposed to obtain various kinds of wavefront shaping, including anomalous refraction [8], reflection [9], vortex wave generation [10; 11; 12], and focusing [13; 14; 15]. These metasurfaces can be classified into two categories, according to their working mechanisms. The first is transmissive metasurfaces [16; 17; 18], where the efficiency is a major concern, due to the intrinsic absorption loss in materials. The second is reflective metasurface [19; 20], which could avoid absorption and usually exhibit a higher efficiency. In 2011, [PERSON] et al. firstly utilized a V-shaped antenna to realize an anomalous reflection based on a phase gradient metasurface [21].  
Following their pioneering work, researchers have devoted extensive efforts into developing reflective metasurfaces with tailored phase distributions for wavefront shaping [22; 23; 24; 25; 26; 27; 28; 29]. However, most of the previous investigations focus on the isotropic reflective metasurface, hindering the application of metasurfaces in the manipulation of light with different polarizations. Therefore, several anisotropic metasurfaces have been demonstrated to tailor the reflective wavefront under illumination with different polarizations in visible, infrared, and THz regions [30; 31; 32]. More recently, researchers have brought the anisotropic reflective metasurface into the microwave regime to realize the polarization-dependent manipulation of microwaves for wireless communication [33].  
In this work, an ultrathin anisotropic reflective metasurface is proposed to independently control the wavefront of \(x\)- and \(y\)-polarized waves at a frequency of 15 GHz, with high efficiency. The anisotropic metasurface is composed of three layers, including a square metal ring with a cross resonator, a dielectric substrate, and a metal ground. The anisotropic responses for reflective \(x\)- and \(y\)-polarized waves are realized by engineering the geometry of the metallic cross resonator. Based on this anisotropic metasurface, a pure polarization beam splitter can be achieved under a quasi-plane wave incidence. Moreover, the principle of the independent manipulation of \(x\)- and \(y\)-polarized microwaves is extended to focusing \(x\)- and \(y\)-polarized components to different positions. The simulation results are in good agreement with the theoretical design. The proposed anisotropic metasurface may have great prospects in the practical application of microwave antennas.