A REFLECTARRAY BASED ON THE FOLDED SIR PATCH-SLOT CONFIGURATION BACKED ON FSS FOR LOW RCS

In this letter, a re∞ectarray antenna based on the folded stepped impedance resonator (SIR) patch-slot conflguration with variable size is presented. A novel frequency selective surface (FSS) in the re∞ectarray as a ground plane for reducing radar cross section (RCS) level is applied. The FSS is based on the folded SIR conflguration. Two prime-focus 15£15 re∞ectarray antennas backed on the folded SIR FSS ground and a conventional ground are designed and manufactured. The radiation performance of a re∞ectarray element backed either by a solid ground plane or a band-stop FSS structure is compared. The measured results demonstrate that the radiation pattern and gain of the FSS-backed re∞ectarray are almost same to its counterpart backed by a conventional ground plane at the operating band of 11.5GHz. The RCS is efiectively reduced in the out of this band when compared with the re∞ectarray with a solid metal ground plane of the same dimension.