Antenna Pattern Measurements to Characterize the Out-of-Band Behavior of Reflector Antennas.

Research was conducted to collect and describe out-of-band antenna pattern data. The research efforts were devoted (1) to deriving valid measured data for a reflector antenna for out-of-band frequencies spanning intervals around the second and third harmonics of the in-band design frequency and (2) to statistically characterize the measured data. The second harmonic data were collected for both polarization senses for the out-of-band frequencies of 5.5 GHz to 7.5 GHz in steps of 0.1 GHz. The third harmonic data were collected for both polarization senses for the out-of-band frequencies of 8.0 GHz to 10.0 GHz in steps of 0.1 GHz. Additionally, in-band data were collected at 2.9, 3.0, and 3.1 GHz for both polarization senses. The measured data were collected on the Georgia Tech compact antenna range test facility with the aid of an automated data logger system designed expressly for efficient collection of broadband antenna data. The pattern data, recorded directly on magnetic disks, were analyzed (1) to compute average gain and standard deviation over selected angular sectors, (2) to construct cumulative probability curves, and (3) to specify the peak gain and the angular coordinates of the peak at each frequency.
Prepared by IIT Research Inst., Chicago, IL.