Development of a 23–230 GHz frequency selective surface for the Microwave Sounder instrument on the MetOp Second Generation mission

The design, predicted and measured performance of an ultra-broadband frequency selective surface, developed to separate spatially the spectral signals in the antenna feed network of the Microwave Sounder instrument, is reported. The low pass filter operates at 45° incidence in 7 discrete bands over the frequency range 23 - 230 GHz. Maximum measured in-band loss is 0.4 dB within the transmission and reflection bands.