Synthetic aperture radar based on digital beamforming

This article introduces a representative of the latest generation of spaceborne synthetic aperture radar (SAR)——Digital Beamforming SAR (DBF-SAR). The technique of DBF will effectively deal with the paradox between high resolution and wide swath, which is the fundamental issue faced by conventional spaceborne SAR systems. Compared with conventional Analog Beamforming technology, DBF is advantageous in aspects including design of antenna pattern with low sidelobes, multi-beamforming, super resolution and adaptive space-time processing. Such advantages provide the technical basis for data acquisition using high-resolution and wide-swath SAR systems. This article takes the current high-resolution TerraSAR system as a reference, gives a primary analysis to the load and satellite of the DBF-SAR with indices of 100~160km swath and 1m resolution, discusses the system design of stripe mode under the azimuth three-beam mechanism, calculates the required power and data rate, analyzes the working modes. This article finally explores the key technologies for the following pre-research of a DBS-SAR system and gives meaningful advices.