Frequency and polarisation selective surface for sub-millimetre wave atmospheric remote sensing

Abstract

A novel Frequency and Polarisation Selective Surface (FPSS) is proposed, which separates two adjacent bands with a narrow transition zone by the staggered separation scheme and is suitable for atmospheric remote sensing. The traditional FSS is transparent in a particular frequency band for both the TE and TM polarisations, while it is opaque in another band for both orthogonal polarisations. The FPSS is introduced in a new splitting scheme that operates above 300 GHz. The channel 420–430 GHz of the TE polarisation and the channel 360–400 GHz of the TM polarisation transmit in the FPSS. In contrast, the band 360–400 GHz of the TE polarisation and the channel 420–430 GHz of the TM polarisation are reflected. The water vapour and the oxygen profiles are detected by the 380 GHz band and the 425 GHz band, respectively. The insertion loss is lower than 1 dB, and the reflection band rejection is superior to 10 dB in the experiment, which determine the sensitivities of the bright temperature by 1.5 (RMS K). The scattered wave of the FPSS is calculated through the far field pattern, the maximum of which is about 5%. The side effect of the scattered wave is able to be ignored in the optical path.