Planar Metamaterial Absorbers for Calibration of Microwave Radiometers for Atmospheric Remote Sensing.

In this work, we present metamaterial-based microwave absorbers fabricated on organic-based printed circuit boards as promising alternatives to traditional, bulky microwave absorbers for the calibration of microwave radiometers for atmospheric remote sensing. Their use is particularly attractive for on-board calibration of sensors on CubeSats and other small satellites. Planar metamaterials can be fabricated with near-unity absorption over a very broad frequency range, and are scalable by tuning the unit cell geometry. Specifically, we describe an approach and initial measurements toward designing a broadband metamaterial emitter operating at millimeter wave sounding channels from 50 GHz 230 GHz, enabling a thin, cost-effective calibration target for millimeter-wave atmospheric remote sensing.