Synthesis of Large Alias-Free Field-of-View Linear Arrays for Synthetic Aperture Interferometric Radiometers

The alias-free field-of-view (AF-FOV) is inversely proportional to the spatial-frequency sampling spacing in the synthetic aperture interferometric radiometers. When the physical size of the antenna elements is large relative to the wavelength, the AF-FOV is limited. This article focuses on extending the AF-FOV from the perspective of array design. By introducing the sampling spacing-compression factor, we define a type of large AF-FOV linear array (LFOVLA) that can generate consecutive spatial-frequency samples with sampling spacing less than the minimum antenna spacing. A simulated annealing (SA)-based algorithm is presented to generate a double AF-FOV linear array (DFOVLA), which has the advantage of generating lower redundancy DFOVLA and reducing time cost compared with the previous method. A general pattern method is also proposed to seek a large DFOVLA directly. The DFOVLA configurations below 26 elements are given. The simulation results show that the DFOVLA has a larger AF-FOV than the traditional array in the synthetic aperture interferometric radiometers.