Accession Number : ADP004633

Title :   Optimum Probe Design for Near Field Scanning of UltraLow Sidelobe Antennas,

Corporate Author : TECHNOLOGY SERVICE CORP SILVER SPRING MD

Personal Author(s) : Grimm,K. R.

Report Date : JAN 1985

Pagination or Media Count : 23

Abstract : An innovative technique has been developed for accurately measuring very low sidelobe antenna patterns by the method of planar near field probing. The technique relies on a new probe design which has a pattern null in the direction of the test antenna's steered beam direction. Simulations of the near field measurement process during such a probe show that -60dB peak sidelobes will be accurately measured (within established bounds) when the calibrated near field dynamic range does not exceed 40 dB. The desireable properly of the new probe is its ability to 'spatially filter' the test antenna's spectrum by reduced sensitivity to main beam ray paths. In this way, measurement errors which usually increase with decreasing near field signal level are minimized. The new probe is also theorized to have improved immunity to probe/array multipath. Plans to use the new probe on a modified planar scanner during tests with the AWACS array at the National Bureau of Standards will be described. (Author)

Descriptors :   *PROBES, *NEAR FIELD, *ELECTRONIC SCANNERS, *SIDELOBES, *DIRECTIONAL ANTENNAS, BEAM STEERING, ERRORS, ACCURACY

Distribution Statement : APPROVED FOR PUBLIC RELEASE