Interferometric Technique for Measuring Terahertz Antenna Phase Patterns

摘要: A quasi-optical interferometric technique capable of measuring antenna phase patterns without the need for a heterodyne receiver is presented. It particularly suited to characterization terahertz antennas feeding power detectors or mixers employing local oscillator injection. Examples recorded at frequencies 1.4 and 2.5 THz using homodyne are To our knowledge, these highest frequency ever recovered. Knowledge both amplitude in far field enable Gauss-Hermite Gauss-Laguerre beam-mode analysis be carried out antenna, importance performance optimization calculations, such as gain beam efficiency parameters design prototype stage development. full description would also required if used feed system near-field far-field transition region. This situation could often arise when device fitted directly back telescopes flying observatories. further benefit proposed simplicity characterizing systems situ, an advantage considerable many situations, components may not removable once assembled. The methodology generic should useful across wider sensing community, e.g., single detector acoustic imaging adaptive array applications. Furthermore, it applicable other EM spectrum, provided adequate spatial temporal stability source can maintained throughout measurement process. Phase information retrieval emergent research areas, band-gap structure characterization, meta-materials research, electromagnetic cloaking, slow light, super-lens well virtual