Compact three-dimensional four-way vectorial steering module for Ka-Band multiple feeds-per-beam satellite payload applications

A compact three-dimensional four-way vectorial steering module using low-temperature co-fired ceramics multi-layer technology, hybrid-integrated with monolithic microwave integrated circuits, for flexible satellite payloads operating in the Ka-band downlink frequency range of 17-22 GHz is presented. The module features digitally controllable actuators and hermetic sealing at a compact size of 26 mm × 44.5 mm × 4.4 mm. For feeding the module with a single input signal, a one-stage four-way Wilkinson power divider was designed incorporating buried resistors, fabricated, and measured. The divider exhibits a measured return loss of better than 13 dB at the input port and 16 dB at the output ports. The output port isolation exceeds 20 dB, the transmission phase difference remains below 3.1 degrees, and the insertion loss is less than 1.2 dB. The vectorial microwave parameters of the module can be adjusted by 344 degrees for phase and 15.5 dB for amplitude, with 5-bit resolution, and at step sizes of 11.25 degrees and 0.5 dB, respectively. The measured results show that the RMS phase and amplitude errors remain below 3.8 degrees and 0.23 dB.