COMPARISON OF ULTRALOW-SIDELOBE-ANTENNA FAR-FIELD PATTERNS USING THE PLANAR-NEAR-FIELD METHOD AND THE FAR-FIELD METHOD

The development of very-low-sidelobe antennas raises the question of w hether or not the planar-near-field method can be used to accurately m easure these antennas. Recently, scientists at several organizations s howed that data taken and processed with the planar-near-field methodo logy, including probe correction, can be used to accurately measure th e sidelobes of very-low-sidelobe antennas. This can be done to levels of -55 dB to -60 dB, relative to the main-beam peak [1]. This paper hi ghlights these results, including a comparison of the far field, from the planar-near-field method, with the far field, found on a far-field range. The test antenna for this study was a slotted-waveguide array, the low sidelobes for which were known. The near-field measurements w ere conducted on the NIST planar-near-field facility.