Wideband and Wide-Angle RCS Reduction of MIMO Antennas Using Compensate-Layered Metasurface for Cube Satellite Applications

In this article, a multiple-input-multiple-output (MIMO) antenna array with wideband and wide-angle radar cross section (RCS) reduction based on compensate-layered metasurface is proposed for cube satellite applications. First, a metasurface with compensated mediums, achieving a broadband and stable 180 +/- 37 degrees phase difference between the x- and y-directions within wide oblique angles for both TE and TM polarizations, is proposed. Second, a wideband, high-isolation, and low RCS $2\times 2$ MIMO antenna based on the metasurface is proposed. On the one hand, two intrinsic modes are excited by integrating the metasurface with a conventional slot antenna. A wideband of |S-11| <-10 dB is obtained from 3.90 to 5.35 GHz. Over 25 dB isolation is achieved within the working band. On the other hand, over 6 dB RCS reduction is achieved from 4.69 to 19.58 GHz with a relative bandwidth of 122.7%. For oblique incident wave within 45 degrees, it has an over 100% relative bandwidth of 6 dB RCS reduction for both TE and TM polarizations. Finally, the MIMO antenna implanted on a cube platform is studied for cube satellite applications. The measurements and the simulations are in good agreement. The wideband and wide-angle metasurface based on compensate-mediums theory is first proposed for MIMO antennas, achieving wideband, high isolation, and wideband, wide-angle low RCS, which can be a candidate for stealth cube satellite application.