Title :
Power densities in the near field of a large antenna focused to infinity
Author_Institution :
Lockheed Martin Corp., Philadelphia, PA, USA
fDate :
1/1/1997 12:00:00 AM
Abstract :
At low-beam elevation angles, measurements of microwave propagation from satellite to ground have exhibited large variations in signal strength under clear weather and cloudy conditions. Large nonuniformities in the three-dimensional (3-D) near-field region of an antenna focused to infinity have been computed. These field nonuniformities interacting with a dynamic turbulent troposphere can introduce phase errors at the antenna aperture, resulting in signal scintillation and loss
Keywords :
aperture antennas; microwave propagation; satellite links; tropospheric electromagnetic wave propagation; 3D near-field region; antenna aperture; antenna focused to infinity; clear weather; cloudy conditions; dynamic turbulent troposphere; field nonuniformities; large antenna; low-beam elevation angles; microwave propagation; phase errors; power densities; satellite-ground path; signal loss; signal scintillation; signal strength; Antenna accessories; Antenna measurements; Antennas and propagation; Aperture antennas; Bismuth; Extraterrestrial measurements; H infinity control; Microwave propagation; Optimized production technology; Satellites;
Journal_Title :
Antennas and Propagation, IEEE Transactions on