Part 1: The basics Phase Sync in Digital Phased Arrays Through Direct RF Sampling

A new synchronisation approach ensures repeatable phase coherence in modular digital beamforming systems using direct RF sampling.

An all-digital beamforming radar system is dependent on the degree to which the transmit and receive channels are synchronised. Since the phases to all channels are applied in the digital domain, there arises a need to establish a known and repeatable phase difference between all the channels. This article presents a methodology to synchronise multiple modular circuit boards, equipped with high speed data converters, to build a concept of a scalable digital beamforming system. This work involves achieving phase repeatability over power cycles by syncing multiple wideband digitiser integrated circuits (ICs), which is a four-transmit and four-receive data converter with high on-chip digital signal processing (DSP) capabilities.