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 whether or not the planar-near-field method can be used to accurately measure these antennas. Previously, scientists at several organizations showed that data taken and processed with the planar-near-field methodology, including probe correction, can be used to accurately measure the sidelobes of very-low-sidelobe antennas. This can be done to levels of -55 dB to -60 dB, relative to the main-beam peak. The present paper highlights 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 the study was a slotted-waveguide array, the low sidelobes for which were known. The near-field measurements were conducted on the NIST planar-near-field facility