A Ku-band variable power divider for reconfigurable satellite antennas

A novel planar version of the classical variable power divider (VPD) comprising two hybrids and two variable phase shifters is described. A significantly improved variable phase shifter, based on a 3 dB hybrid terminated by two sliding non-contacting moveable short circuits, is used in this VPD. The differential phase spreading of such a phase shifter has been reduced to less than one-sixth of the typical transmission line dispersion by compensating short terminations. The device has been modelled by an accurate full wave analysis software available at Alenia Spazio. The measured performance on a breadboard model is flat over a 16% bandwidth and significantly improved with respect to the classical solution. Planar integration, wideband performance, medium-high power handling capabilities and low loss are some of the key features of this VPD which is presently undertaking a space qualification process