Economy of Near-Field Antenna Measurements

Authors: Gerald Hickman

Publication: AMTA 1979

Copyright Owner: NSI-MI Technologies

Near field antenna measurements have long been of interest to the antenna community and of particular interest to those in the design and measurement of antennas. Efforts in this area using analog computers for data reduction were already under way in the late 19SO's. These applications were limited, primarily due to the limitations of the analog computer. Two planar near field probe positioners were built by Scientific-Atlanta during this period and delivered; one to Martin Denver and one to the Georgia Institute of Technology. These units were used for development on planar near field measurements. The unit at Martin Denver .was-also used by the Bureau oL Standards. ExperimentaLwork at Georgia Tech led to Dr. Joy's thesis on spacial sampling and filtering.1 This work on sampling was· particularly important because it gave an understanding of the required data density for meaningful transformation by digital computer. Numerical integration is a time and core intensive process and it was the utilization of the Fast Fourier Transform in the early 1970 1 s that made the digital computer a viable approach to the problem.