Millimeter-Wave Imaging Using a Rotating Dynamic Antenna Array and Noise Illumination

We present a novel approach to millimeter-wave imaging that combines a new dynamic antenna array concept with active illumination by means of noise signals and interferometric image formation. The concept is based on a sparse linear array of receiving antennas that is dynamically rotated about its centroid, combined with three noise transmitters that illuminate the scene. Cross-correlations of the scattered signals received by individual array elements provide spatial frequency samples of the scene, from which the scene can be reconstructed via inverse Fourier transform. As the spatial frequency sampled by an antenna pair is dependent on the antenna baseline vector, dynamic rotation of the linear array generates sampling curves in the spatial frequency domain, providing a denser sampling function and a more accurate scene reconstruction. While traditional static interferometric imaging arrays utilize nearly an order of magnitude fewer antenna elements than phased arrays, our dynamic array concept relies only on a sparse linear array, further reducing the number of hardware elements required. We discuss the design of a 38 GHz dynamic antenna array imaging system and present measurements of multiple reflecting objects.