Patent ID: 8507836
Filing Date: 2013-08-13
Classification: G01J,H01Q

Abstract:
1. A lensless imaging system comprising: an aperture array having a first side exposed to a scene to be imaged, and having a second side from which is provided an output representative of original frequency components of electromagnetic energy from the scene and local phase differences of electromagnetic energy from the scene; a planar array, of individually addressable antenna elements, that is disposed to receive the output from the aperture array; a local oscillator providing a reference frequency output incident on the planar array so as to create a heterodyne difference signal between the reference frequency and each original frequency component present at each of the antenna elements; a first passband filter coupled to a first selected set of adjacent antenna elements, corresponding to a phase reference, of a cluster in the planar array to provide a first intermediate frequency output for the first selected set of adjacent antenna elements; wherein (i) the reference frequency has been selected to cause the intermediate frequency output to correspond to a selected frequency sub-band of the original frequency components and (ii) the cluster corresponds to a pixel in an image of the scene; a second passband filter coupled to a second selected set of adjacent antenna elements of the cluster in the planar array to provide a second intermediate frequency output for the second selected set of adjacent antenna elements; a phase detector having first and second inputs coupled to the first and second intermediate frequency outputs respectively and having an output representative of the difference in phase of each original frequency component, within the selected frequency sub-band, present in the first set of elements and present in the second set of elements in the cluster; and a signal analyzer coupled to the phase detector output to determine an amplitude value associated with the cluster and therefore of the corresponding pixel in the image of the scene.