GlobalStar II RX L-Band Antenna Spherical Near Field Measurement

eams on the Elevation plane, and a lower effect for theones on the Azimuth plane.Figure 19: Beam13 – 0° vs 180° - EL 0.05degTheta Sin(Phi)806040200-40 -20 0 20 40Theta Cos(Phi)Figure 16: Beam9 – 0° vs 180° - EL 0.05degTheta Sin(Phi)806040200-40 -20 0 20 40Theta Cos(Phi)Figure 17: Beam9 – 0° vs 180° - EL 0.1degTheta Sin(Phi)40200-20-400 20 40 60 80Theta Cos(Phi)Figure 18: Beam13 – 0° vs 180° - EL 0.1degTheta Sin(Phi)402004. Antenna Performances Comparisons: theconclusion of the test range assessment was thecomparison between the performances obtainedby the post-processing of the data coming fromthe three different facilities and comparing themwith the total uncertainties defined before. Allthe evaluated delta fall in the range of the totaluncertainty of the relevant facilities (RSS ofeach facility uncertainty), showing that approachused to assess the SNF error budget, produced,likely, a “pessimistic” scenario of the facilityperformances.7. SUMMARYA general description of the New Spherical Near Fieldinstalled and validated in TAS-I Rome to support theGLB2 L-band RX Active antenna is shown. Thecomparisons of the Active Antenna Breadboardmeasurements, in terms of copolar and cross polarpatterns and the post-processing data show a very goodconvergence. This ensured a successful test facilityvalidation and the definition of performance uncertaintybudgets for the GBL2 antenna production program.8. REFERENCESHansen, J.E. Editor (1988), Spherical Near Field AntennaMeasurement, Peter Peregrinus Ltd.Allen C. Newell, Greg Hindman, The Alignment of aSpherical Near Field Rotator using ElectricalMeasurements, in the proceedings of the 19 th annualAMTA Meeting and Symposium, 1997Allen C. Newell, Greg Hindman, The Effect ofMeasurement Geometry on Alignment Errors in SphericalNear Field Measurements , In the proceedings of the 21 thannual AMTA meeting and Symposium, 1999.Allen C. Newell, Daniël Janse van Rensburg, Estimatingthe Uncertainties due to Position Errors in SphericalNear-Field Measurements, in the Proceedings of the 25 thannual AMTA Meeting and Symposium, 2003Allen C.Newell, Greg Hindman, Quantifying the Effect ofPosition Errors in Spherical Near-Field Measurements,in the proceeding of the 20 th annual AMTA meeting andSymposium, 1998.-20-400 20 40 60 80Theta Cos(Phi)