Grating lobe control in randomised, sparsely populated MIMO radar arrays

Randomisation of element positions in a sparsely populated, non-uniform antenna array is a well-known approach in communication systems for controlling grating lobes and allowing improved spatial resolution for a given number of antenna elements. MIMO array techniques have been applied more recently to radar systems with a view to improving the versatility and performance, particularly angular resolution, of a system with a given number of elements. A sparsely populated, non-uniform MIMO array would therefore seem a logical and attractive combination, though its performance is rather more difficult to predict and less easy to control because of geometrical constraints. This study sets out to examine the spatial sidelobe performance and potential for grating lobe control of a sparsely populated MIMO radar array architecture using antenna position randomisation to suppress grating lobes.