Design of a slot array antenna with ultra-wideband low-scattering characteristic

Abstract

This paper presents a 4 × 4 slot array antenna with ultra-wideband low-scattering characteristic, which integrates a metasurface based on the multielement phase cancellation (MEPC) method. Limited by the characteristics of the slot antenna array, the contradiction between the ideal radiation performance and the requirement of low radar cross section (RCS) has not been well resolved. Therefore, in this paper, a MEPC-based metasurface is designed as the cover-layer of the proposed antenna, which can disperse the reflected energy to more directions without degrading the radiation performance. The proposed antenna operates in a bandwidth of 3.89–4.00 GHz with a maximum gain of 14.3 dBi. Additionally, the 7 dB RCS reduction bandwidth for TE/TM polarization at normal incidence is 5.5–40 GHz (f h / f l = 7.27:1), achieving ultra-wideband out-of-band RCS reduction. Furthermore, low-scattering performance can remain stable at large-angle oblique incidence. To verify the feasibility of the proposed design, a prototype is fabricated and measured for demonstration. The simulated and measured results are in good agreement.