Performance of phased array antennas with mechanical errors

The performance of planar phased-array antennas with two classes of mechanical errors was investigated. Errors in array element positions as a result of structural distortions are considered to be predictable or measurable and, therefore, deterministic. Two fundamental modes of distortion of the planar structure were assumed: a single curvature (bent slab) and a double curvature (bowl-shaped) distortion form its ideal configuration. Detailed calculations for the distorted arrays reveal that the primary effects of such distortion or mechanical errors on the antenna radiation pattern are the loss of peak response in the scan direction and the broadening of the mainlobe, while the far-out sidelobe structure remains relatively intact. The antenna directivity and the average sidelobe level of the distorted array were calculated by a method of graded resolution in the direction cosine space.<>