Miniaturized Dual-Polarized Metasurface Antenna With High Isolation

Abstract

A dual-polarized (DP) metasurface (MTS) antenna with miniaturized radiating aperture is proposed for polarimetric synthetic aperture radar. The antenna consists of an MTS radiator and a cross aperture antenna. Characteristic mode analysis (CMA) is utilized to analyze the working mechanism of the MTS radiator and to guide the miniaturization of the radiating aperture. Then, the CMA is used for the optimization of the DP cross aperture antenna to achieve better isolation. A reduced radiating aperture of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$0.37{\lambda _0} \times 0.36{\lambda _0}$</tex-math></inline-formula> is realized with a thickness of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$0.13{\lambda _0}$</tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\lambda _0}$</tex-math></inline-formula> is the free-space wavelength of central frequency). The simulated and measured results show that the DP antenna yields 10 dB fractional bandwidths of 43.72% for Port H and 38.65% for Port V. The cross-polarization levels are better than –23 dB at 9.6 GHz, and the isolation between the two ports remains above 35 dB over the whole operating bandwidth.