ARC range test facility
AssigneeThe United States of America as represented by the Secretary of the Air Force
InventorsPeter R. Franchi, Harvey E. Tobin
Life of this patent
Estimating the term…
Abstract
In order to measure the far field antenna pattern of a phased array antenna, the phased array is focused at a probe antenna which is a specific distance away from the aperture. The antenna pattern is then measured by moving the probe antenna on a constant focal arc. This arc minimizes phase aberrations due to defocusing error. To minimize amplitude errors, the pattern of the probe antenna is carefully matched to compensate for the variation induced amplitude error.
Claims8
A process for measuring a phased array antenna's far field antenna pattern which is exhibited as electromagnetic power measured in watts per square centimeter by a beam emitted by the phased array antenna wherein said phased array antenna has an antenna center, said process comprising the steps of:
- focusing the beam onto a probe antenna which measures the beam, said probe antenna being positioned at a distance R, where R is a distance between said probe antenna and the antenna center of the phased array antenna given by ##EQU38## where:
- is measure of the phased array antenna's aperture and .lambda. is a measure of operational wavelength of the beam;
- measuring the electromagnetic power of the beam with the probe antenna to identify a pattern of electromagnetic power emitted there from;
- moving the probe antenna to different positions that are on a focal arc of the phased array antenna;
- and
- repeating the focusing, measuring and moving steps.
Dependencies are inferred from the claim text.