A novel polarization-independent Frequency Selective Surface(FSS) is designed by altering traditional Y slot element arrangement. Based on the modal matching method

the frequency response of this structure is analyzed to obtain the plot of frequency versus transmission coefficient. With coating technology and lithography

the FSS samples of conventional and improved arrangement are made respectively. The tests under different polarized waves at 30° incidence angle are given in the microwave darkroom. The measured curve shows good agreement with the simulated curve. Both of the numerical analysis and experiment results show that the response of FSS with the conventional arrangement is changed very distinctly with the source polarization

the increase of transmission loss is -1.09 dB; but with the modified structure

the increase is only -0.25 dB. The improved Y element array can be resonant at a single frequency and has good polarization independency. It provides a new design method for that the polarization situation of a source is completely unpredictable.