Focal Arc Pattern Measurements,
Abstract
Problems exist with the measurement of large aperture antennas due to the far field requirement. This paper discusses a new method to measure a phased array at about 1/10 the normal far field. The basic idea involves focusing the test array, at probe, antenna a distance R away from the aperture, and then, measuring an antenna pattern by moving the probe antenna on a constant focal arc given by R cos(Theta). This arc minimizes phase aberrations due to defocusing error. To minimize the amplitude errors, the pattern of the probe antenna is carefully matched in order to compensate for the 1/R variation induced amplitude error. The application of this technique will enable arrays to be measured in anechoic chambers, allowing convenient classified testing, while avoiding the effects of weather, and will reduce the risks inherent in the high power testing on transmit. The results of a computer simulation is presented that characterizes the validity and limitations of the technique.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1992
- Accession Number
- ADP007430
Entities
People
- Harvey Tobin
- Peter R. Franchi
Organizations
- Rome Laboratory