Compact Single and Dual Broadband Reflective Type Linear Cross Converters at Terahertz Regime

This paper presents two new reflection type linear cross converters at the terahertz (THz) waveband. The proposed converter possesses the advantages of compact and simple unit cell geometry, which can be optimized easily for single wideband and dual broadband polarization conversion. The unit cell of the converter comprises anisotropic geometry of double E-shaped resonators. The designed structure converts a linear polarized incident wave into cross-polarization over the frequency range of 0.67 to 1.65 THz (84.5 %) with above 90 % polarization conversion ratio (PCR). At three frequencies of 0.73, 1.11, and 1.55 THz near 100 % polarization conversion is achieved. The converter exhibits stable polarization conversion characteristics for incidence angle > 35°. A pair of parallel slits are placed along the length of the E-shaped resonators to obtain a notch in the converter's response. The modified metasurface exhibits dual-band cross-polarization conversion between the frequency ranges of 0.67-1.06 THz (45.1 %) and 1.37-1.74 THz (23.8 %).