Design considerations on a sparse array antenna for Ka-band spaceborne SAR applications

Introducing sparsity in a spaceborne Ka-band SAR antenna

“…It is shown that a density taper along the elevation dimension with a fill factor of 90% with respect to the benchmark array still allows satisfying the mask for the receive pattern. Such a taper in combination with the approach described in [2] to implement sparsity along the azimuth dimension of the antenna would allow for a substantial reduction of the active modules. Topics of further investigation are the fine-tuning of the density tapers to avoid mask violations while scanning, the verification of the 2D patterns for scanning off elevation plane, and the combination of sparsity in elevation and azimuth.…”

“…In [2] the problem of introducing sparsity in a Ka-band phased-array SAR antenna able to scan +/-10° in elevation and +/-2° in azimuth was presented. The general mission and antenna requirements are reported in [2].…”

“…The general mission and antenna requirements are reported in [2]. As benchmark for the transmit and the receive radiating apertures, two arrays of 320 x 96 and 320 x 288 elements, respectively were considered, with periods of 0.74l in azimuth and 0.83l in elevation.…”

“…An approach to decrease the number of active modules in the azimuth direction was presented in [2]. This solution consists of: 1) introducing a limited number of subarrays with different lengths (typically 4 to limit manufacturing complexity), 2) calculating all possible different linear arrays of 320 elements composed of those subarrays, and 3) filling the aperture with a random selection of those linear arrays.…”