INTELSAT VII hemi/zone antennas (design and results)

The authors describe the design of the INTELSAT VII (I-VII) hemi/zone (H/Z) antennas, and the results of the proto-flight model acceptance testing. The correlations between the measured and calculated data, and a discussion of the results are also presented. the I-VII H/Z antennas operate at C-band and consist of two antennas, one for the receive band and the other for the transmit band. Each antenna has a single offset reflector fed by a multifeed array with over 100 feed horns. The antennas produce circular polarization. The antennas have a sixfold frequency reuse, serving four zone and two hemi coverage areas. The hemis are spatially isolated, as are the zone beams. Hemis and zones are isolated from each other via polarization. Measured and calculated farfield patterns for the largest receive (alpha) zone coverage are presented.<>