This paper presents a novel linear to cross reflective type polarization converter for X and Ku-band applications. It comprises a 45° tilted resonating patch on the top of a thin FR-4 substrate, which is terminated by PEC on the other side. The converter exhibits Polarization Conversion Ratio (PCR) greater than 90% over 10.17 GHz bandwidth (from 8.2 to 18.37 GHz ) with 76.5% fractional bandwidth (FBW). Multiple surface plasmonic resonances are responsible for uniform PCR over the broadband. The reason behind the ideal response at resonant frequencies is illustrated by surface current distribution analysis. This design is obliquely stable up to 30°, with a minimum of 87% PCR, for the transverse electric (TE) mode and the same is observed for transverse magnetic (TM) case. The proposed linear-cross converter is compact with periodicity 0.213λL and thickness 0.07λL, where λL corresponding to the free-space wavelength of lowest bandwidth frequency. RCS analysis has been performed for monostatic and bistatic cases to demonstrate the capability of the proposed design in EM shielding applications. © 2020 IEEE.