COMSTAR millimeter-wave propagation measurements
Abstract
The use of millimeter frequencies for Earth-to-space communication links will soon be a reality. It has been long known that precipitation will be a problem because of the relatively large attenuation caused by rainfall along the propagation path. Some of the latest experiments to provide needed propagation data have involved the COMSTAR Millimeter-Wave Beacons which were part of three synchronous orbit satellites launched by COMSAT Laboratories. The Propagation Branch of the Electromagnetic Sciences Division utilized these beacons to obtain attenuation ratio data at 19 and 28 GHz and phase dispersion data at 28 GHz. This report is a station report covering the 1 year measurement program and various theoretical analyses. The attenuation ratio data was in fair agreement with the theory; however, considerable variation was found at low attenuations. Phase dispersion measurements were in reasonable agreement with theory considering the small magnitude of the phase dispersion across a 1 GHz bandwidth at 28 GHz. From a practical point of view, for a given propagation path, the path attenuation will be very large before phase dispersion becomes a problem for most systems.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- April 1980
- Bibcode:
- 1980STIN...8117319T
- Keywords:
-
- Attenuation;
- Extremely High Frequencies;
- Microwave Transmission;
- Millimeter Waves;
- Rain;
- Spacecraft Communication;
- Wave Propagation;
- Electromagnetic Wave Transmission;
- Synchronous Satellites;
- Communications and Radar