Research on The Relation between the Beampattern and Clutter Distribution of Curved Surface Array for Airborne Conformal Array Radar

To demonstrate the performance of beam-pattern and clutter distribution for airborne conformal radar due to the bending effect of carrier, the half-uniform circular array and fan-shaped array with the same radius are compared in the array synthesis characteristic, in the case of vertical side-looking. It is found that the edge elements have little contribution on the main-beam gain, alternatively, but enhances the side-lobe level so obvious that the combination property of the radar and aperture efficiency suffers degradation. Simultaneously, the inherent relation between the beam-pattern and the clutter spread is proved that the beam distortion resulting from the curved surface is the core factor on the clutter distribution inhomogeneity, through strict theoretical reduction. On the basis of the previous discussion, the additional structure of manufacture and installation, which would increase the physical dimension, is considered to enlarge the space between the adjacent radiators. In particular, the grating-lobe has appeared on the far-field pattern and made further efforts on the clutter distribution for Conformal Array Radar (CAR), in the condition of the reasonable element interval. One to be noted is that the grating-lobe clutter is folded to the main-lobe clutter region under the specific Pulse Repetition Frequency (PRF). To avoid the foldover of clutter, the PRF of CAR can be optimized and the related simulation is conducted to verify the effectiveness of the proposed method.