Digital beamforming antenna array with polarisation multiplexing for mobile high-speed satellite terminals at Ka-band

In this contribution, a planar antenna array terminal for mobile satellite communications at Ka-band is proposed. This Earth station on mobile platform uses separate transmit and receive apertures to obtain a flat design well suited for aeronautical applications. Digital beamforming is applied for fast beam scanning, tracking, and enhanced post-processing capabilities. The active antenna elements exhibit dual polarisation to comply with a four-colour spot beam arrangement commonly used by high-throughput satellites. Advanced frontend packaging concepts for a high integration density enable half wavelength element spacing. This prevents grating lobes and yields a large scanning range. A modular approach allows to flexibly adapt the array size to the application specific needs. An 8 × 8 receiver (Rx) array at 20 GHz and a 16 × 3 transmitter array at 30 GHz are demonstrated. The measured results obtained in conjunction with inter-element decoupling validate the approach. The principal suitability of the Rx array for the intended application is tested in a field experiment.