Characterizing a WR-1.5 diagonal horn antenna using photo-induced coded-aperture imaging

We report a novel approach using terahertz (THz) photo-induced coded-aperture imaging (PI-CAI) technique to characterize a WR-1.5 (500-750 GHz) diagonal horn antenna at 590 GHz. The measured antenna beam profiles show decent Gaussian shape and propagation properties, as expected. Antenna far-field radiation patterns extracted from beam images agree well with theory and simulation. On the basis of the imaging results, the antenna Gaussian coupling efficiency (i.e., Gaussicity) is calculated to be ~84%. The reported approach has great potential for fast and accurate characterization of THz horn antennas.