Citation
Abstract
Microwave holography has proven to be a powerful technique for various evaluations, diagnostics, and RF performance improvements for large reflector antennas. This technique utilizes the Fourier transform relation between the complex far-field radiation pattern of an antenna and the complex aperture field distribution. Resulting aperture phase and amplitude distribution data can be used to precisely characterize various crucial performance parameters, including panel alignment, panel shaping, subreflector position, antenna aperture illumination, directivity at various frequencies, and gravity deformation effects. The methodology of the data processing presented in this article was developed at JPL and has been successfully applied to the DSN 34-m beam waveguide antennas. A companion article in this issue (Rochblatt and Seidel) describes the application of this technology to the DSS-13 antenna. The antenna performance was improved at all operating frequencies (wide-bandwidth improvement) by reducing the main reflector mechanical surface rms error to 0.43 mm. At Ka-band (32-GHz), the estimated improvement ts 4.1 dB, resulting in an aperture efficiency of 52 percent. The performance improvement was verified by efficiency measurements and additional holographic measurements.
Details
- Volume
- 42-108
- Published
- February 15, 1992
- Pages
- 235–252
- File Size
- 895.3 KB