The optimization design for microwave wide band blackbody calibration target

The microwave wide band blackbody calibration target applied for the microwave radiometer´s pre-launch calibrations are optimized with its electromagnetic parameter - emissivity through the radar cross section (RCS) simulations based on the sub-grid finite difference time domain (FDTD) method. The optimization results indict that round wedge is better than the square one, the best ratio for height to bottom radius is 4:1 for the wide band from 10 GHz to 26 GHz, and the absorbing material´s gradual thickness coating and multilayer coating are helpful to guarantee the uniform distribution of surface temperature while keeping a higher emissivity.