A new miniaturized frequency selective surface designed for Ku-band absorption and low-frequency bandpass

This article designs a new miniaturized frequency selective surface (FSS) for Ku-band absorption and low-frequency bandpass. The miniaturized frequency selective surface (MFSS) consists of a periodically arranged unit structure, each unit consisting of an upper three-dimensional absorbing structure and a bottom two-dimensional FSS. The upper layer is a bent-closed structure that mainly provides over 90% absorption in the Ku-band. The underlying structure is a FSS in which it acts as a bandpass filter in the transmission band (2.9-3.9 GHz). The unit-cell dimension of the MFSS is 0.091 lambda(0) x 0.091 lambda(0) x 0.054 lambda(0) (lambda(0) is the free-space wavelength at the resonant frequency). Due to its small size, MFSS can effectively avoid grating lobes and maintain good angular stability. Finally, the actual measurement verified that the MFSS has good characteristics.