Formation and Side Lobe Suppression of Scanning Beams for Non-coplanar Distributed Array

This paper proposes a beam forming method and a side lobe suppression method for non-coplanar distributed arrays((NCOPDAs)). In the simplified analyzing model extracted from the application model, two same uniform linear arrays are served as the subarrays, and their excitation conditions and scanning patterns at different angles in the airspace are deduced and computed respectively. Then the scanning beams of two subarrays are adjusted to point in the same direction respectively to ensure that two subarray’s electric fields have the same phases, so that they can be summed up to form the scanning beams. Finally, the excitation conditions for the scanning beam synthesis are obtained and verified to be valid. Further, via the idea of band-pass filtering, the scanning beam is processed with the adaptive Sa function filtering factor which is equal to the width of the beam to maximize the preservation of the main lobe, and filter out and suppress the high side lobe. The processed measured scanning patterns of the linear NCOPDAs in different states all show the side lobe level <-13dB, which verifies the effectiveness and flexibility of the proposed methods.