Spherical Near-field Measurement and Far-field Characterization of a 300 GHz Band Antenna Based on an Electrooptic Probe with Compact Tabletop Robotic Arm

We demonstrate the photonics-based near-field measurements and far-field characterization of a horn antenna operating at 300 GHz based on a spherical scanning system. An electrooptic probe, which consists of an optical fiber and a small organic crystal, is mounted on a 6-axis tabletop compact robotic arm for the scanning. The far-field distribution calculated from the measured spherical near-field distribution without probe correction agrees well with the simulation results.