Implementation of an Adaptive Wideband Digital Array Radar Processor Using Subbanding for Enhanced Jamming Cancellation

Subbanding technique has been applied in wideband (WB) digital array radar systems to address the challenge of high-speed signal processing and WB jamming cancellation. This article reveals that the well-established subband decomposition by polyphase subband filtering could still leave jamming decorrelation post subbanding, which would deteriorate the jamming cancellation performance. A novel implementation of the subbanding processor is then proposed by isolating digital down conversion incorporated in the subbanding operation and performing it at baseband explicitly. This method provides flexibility to process segments of the digitized spectrum, which accommodates radar receivers to contemporary requirements of frequency agility. This article proceeds to propose a joint jamming cancellation scheme for use in the complicated real-world electronic warfare scenario including both mainlobe and sidelobe jamming. The jamming cancellation performance is evaluated by simulation with a detailed investigation on jamming decorrelation mitigation and subbanding implementation consideration. More results are shown by testing the cancellation scheme on data collected with an experimental airborne WB digital array radar in a multijamming scenario toward sea surface targets.