Hemispherical power gain pattern measurements at 7.5 GHz

A technique is described for measuring the complete hemispherical power-gain radiation pattern of a 2.44-m diameter paraboloidal reflector antenna mounted atop a mobile small earth terminal operating at 7.5 GHz. Antenna power-gain data were measured versus azimuth and elevation angles with the earth terminal centered on a heavy-duty turntable flush with test range ground.Test site illumination was achieved with airborne transmitting antennas. Conventional and statistical power-gain patterns are presented for left-hand circular polarization and cross polarization. Results indicate that similar systems cannot rely upon orthogonal polarization to provide isolation or compatibility beyond the angular region of the main lobe.