Electronic protection for digital shared aperture array radar

We have developed a digital shared aperture array radar architecture which supports sub-aperture partitioning of a conformal array to improve time energy management for achieving radar search and track functions over 360 degree azimuth coverage. The digital array system consists of a plurality of digital transmit sub-arrays and digital received sub-arrays. For transmit operation, different frequencies or orthogonal waveforms can be employed for different apertures using the array control commutator. For receive operation, the sub-arrays are selected for different apertures using the receive data commutator. Essentially, the digital shared aperture supports dynamic partitioning of the aperture for multifunction applications. In this paper, we address these capabilities in the electronic protection (EP) against electronic threats, i.e. jamming and deception. Digital array radar provides digital degrees-of-freedom (DOFs) for transmit as well as for receive. These DOFs are selected by the commutators to support transmit and receive electronic protection. The receive DOFs are used for adaptive processing in jammer cancellation. These DOFs can be exploited in a number of ways through sector selection and digital beamforming to support several advanced processing architectures and algorithms. The digital array capabilities can also be exploited in monitoring jamming spectrum and estimation of the corresponding directions-of-arrival (DOAs). Digital array radar has transmit DOFs which can be used to form a transmit beam with nulls towards the deceptive jammers and separate decoy beams formed towards the deceptive jammers.