Indoor Automatic F-16 Fire Control Antenna and Radome Test Facilities

Authors: Joseph J. Anderson

Publication: AMTA 1982

Copyright Owner: NSI-MI Technologies

MI Technologies was selected by the United States Air Force to design and install a complete turn-key test facility for depot maintenance support of the F-16 fighter aircraft. These facilities have been installed at Hill Air Force Base, Utah. Four complete facilities have been supplied, each consisting of a Series 2020 Antenna Analyzer and a Series 5750 Compact Antenna Range. Two facilities are configured for antenna testing and two for radome testing.

This paper describes the equipment furnished for this program. The hardware is discussed as well as the special software designed to perform specific radome and antenna tests.

Conceptual Analysis of Radar Cross-Section Measurments on Compact Ranges

Author: Doren W. Ress, Richard c. Johnson

Publication: AMTA 1982

Copyright Owner: NSI-MI Technologies

A strong emphasis is now being placed on techniques for reduction of radar cross-section, A missile or aircraft which is invisible to radar has an important strategic advantage. With this fact in mind, the user of a weapons system may place an upper limit on the radar cross-section that he will permit his missile or aircraft to have. The designer must then make use of "stealth technology" to reduce the cross-section to an acceptable level, In order to verify the design, radar cross-section measurements must be made. Thus the current emphasis on cross-section reduction leads to an important need for accurate and reliable methods of measuring radar cross-section.

In this article a method of radar cross-section measurement is described. It utilizes a compact range configuration, More widely used as a tool for measuring the radiation patterns of microwave antennas, the compact range can also be applied to the problem of radar cross-section measurement. A heuristic development which illustrates the principles of compact range operation is presented and the coupling equations for both the antenna measurement and the radar cross section measurement cases are derived.

A Precision Optical Range Alignment Technique

Author: Stanley W. Zieg

Publication: AMTA 1982

Copyright Owner: NSI-MI Technologies

Spherical near-field testing and other specialized antenna measurements require precise range and positioner alignment. This paper presents a method based on optical techniques to conveniently measure and monitor both range alignment and the positioner axis orthogonality and intersection. The hardware requirements consist of a theodolite and a unique target mirror assembly viewable from either side.

Field Probe Measurements and Stray Signal Evaluation of a Spherical Near-Field Range

Author: Doren w. Hess

Publication: AMTA 1982

Copyright Owner: NSI-MI Technologies

Just as with far-field or compact ranges, it is important to evaluate spherical near-field ranges with electromagnetic field-probe measurements. Recall that the fundamental motion for utilizing the spherical near-field measurement technique is to permit antenna measurements to be made at short range lengths, relieved from the constraint of the far-field criterion. Just as the illumination function in the test zone of an ideal far-field range is a uniform planar wavefront, the ideal illumination function for a near-field range is a spherical wavefront from an elemental dipole. The field probe measurements provide a quantitative and qualitative assessment of the deviation of either a near-field or far-field range from ideal conditions.

In this presentation the results from a program of field probe measurements for an experimental spherical near-field range are reported. A comparison is made between stray signal effects assessed by field probing the near-field range and by repeating pattern measurements at different range lengths. The two methods show consistent conclusions on the extraneous signal level. Differences and similarities between a spherical near- field range and a compact range are illustrated with field probe measurement data that strikingly reveal the basic difference between the two techniques.