What is beamforming?
Beamforming is a spatial signal processing technique applied to multi-element antenna arrays (phased arrays) that shapes the radiation pattern of the antenna in a desired direction. By carefully weighting the phase and amplitude of each antenna element's signal, beamforming creates constructive interference in the target direction and destructive interference in others, effectively focusing energy like a searchlight rather than illuminating everything equally like a lightbulb.
Analogue vs. digital beamforming
Analogue beamforming applies phase shifts in the radio frequency (RF) domain using phase shifters — hardware components that delay the signal. This produces a single steerable beam efficiently but cannot support multiple simultaneous beams from one array.
Digital beamforming converts each antenna element's signal to digital form, then applies complex weights (phase and amplitude) in software, enabling the simultaneous formation of multiple independent beams pointing in different directions from the same physical array. This is what enables a LEO satellite to serve thousands of user terminals with different beam directions simultaneously.
Satellite applications
On the space segment, digital beamforming in HTS and LEO satellite payloads enables dynamic spot beam allocation — directing more power and bandwidth to high-demand areas in real time. On the ground, flat-panel phased array terminals (Starlink, Viasat, OneWeb) use beamforming to electronically track fast-moving LEO satellites. Beamforming also enables spatial multiplexing in multiple-input multiple-output (MIMO) satellite systems, a key enabler for next-generation throughput.