Wideband and large incident angle wave transparent material based on frequency selective surface with miniaturized elements

Abstract

Different from the traditional frequency selective surface, the working frequency of a frequency selective surface with miniaturized elements (mFSS) is based on the intrinsic capacitance and inductance of its unit cell, but not the structure resonance. Focusing on the application of mFSS in wave transparent material (WTM), we have designed a band-pass WTM with unit cell of metal patch and wire, analyzed their intrinsic capacitance and inductance, and explored the parameters of the mFSS unit and its equivalent circuit on the performances of WTM. A bandpass WTM sample working at 10 GHz is designed and fabricated. Measurements demonstrate that the sample is wideband, insensitive to the incident angle, and polarization independent; the -1 dB bandwidth is over 40% at normal incidence and up to 20% even at large incident angles 60°. Experimental results are in good agreements with the calculations. The advantages of mFSS based WTM can expand its applications in microwave engineering, especially the radomes.