Phase Compensation of Composite Material Radomes Based on the Radiation Pattern

Abstract

Some compensation methods have been proposed to mitigate the degradation of radiation characteristics caused by composite material radomes, however most of them are complex and not applicable for large radomes, for example, the modification of geometric shape by grinding process. A novel and simple compensation strategy based on phase modification is proposed for large reflector antenna-radome systems. Through moving the feed or sub-reflector along axial direction opportunely, the modification of phase distribution in the original aperture of an enclosed reflector antenna can be used to reduce the phase shift caused by composite material radomes. The distortion of far-field pattern can be minimized. The modification formulas are proposed, and the limitation of their application is also discussed. Numerical simulations for a one-piece composite materials sandwich radome and a 40 m multipartite composite materials sandwich radome verify that the novel compensation strategy achieves satisfactory compensated results, and improves the distortion of the far-field pattern for the composite material radomes. For one-piece dielectric radome, more than 60% phase difference caused by radome is reduced. For multipartite radome, the sidelobe level improves about 1.2 dB, the nulling depth improves about 3 dB. The improvement of far-field pattern could be obtained effectively and simply by moving the feed or sub-reflector according to phase shift of the radome.

Design of Tunnel Initial Support in Silty Clay Stratum Based on the Convergence-Confinement Method

“…In practical engineering, stability analysis is usually evaluated from two aspects: the displacement of weak surrounding rock and the stress of supporting structure caused by tunnel construction. However, the existing research on supporting technology has mainly focused on the excavation of mine tunnels, especially tunnels under harsh geological conditions, such as extremely weak broken rock masses and soft soil [2][3][4], high tectonic stress, and other mine lanes [5][6][7][8]. The existing design methods of tunnel supporting structures mainly include the distributed ground pressure approach, subgrade reaction approach, and convergence-confinement method (CCM) [9].…”

Far‐Field Pattern Tolerance Analysis of Reflector Antenna with Random or System Error Based on Interval Arithmetic

“…The electrical performances of antenna with thermal deformations caused by solar radiation are calculated at different time in a day [10] . An optimization design [11] and compensation [12] of large reflector antenna and radome are proposed by considering gravity deformation at different reflector working angles. Wang discussed the machining errors of different paneled forms of the reflector and estimated the electromagnetic performances [13] .…”