Abstract
In this paper, a method based on the Zernike distribution and the optical aberration is proposed to investigate the effects of the distribution characteristics of surface distortions of a reflector antenna on its electromagnetic performance (EMP). For large-scale errors, an analytical model is introduced to describe the arbitrary distortions, based on the orthogonal Zernike polynomials. The effects of error distribution described by the Zernike series on typical EMP are analyzed. The numerical results indicate that the distortions in the distribution feature of defocus or spherical aberration have a greater impact on gain, and the distribution feature of tilt or coma mainly influences boresight offset; the distribution feature of defocus, astigmatism, and spherical aberration has a greater impact on sidelobe levels. The results indicate that the beam contour patterns are related to the distribution forms of distortions and are similar with the same aberration feature. On the basis of the Seidel aberration, the relationships between typical EMP and the aberration coefficient are presented. Based on these, the error profile of the primary influence and the approximate feature of EMP can be determined, and the antenna performance can be predicted in a simple manner.
Highlights
With the development of radio astronomy and deep space exploration, the requirements for the resolution and sensitivity of the reflector antenna are raised
Reflector surface errors are inevitable, and they may be introduced by manufacturing tolerances or structural deformations caused by environmental loads [5, 6]
We mainly focus on the descriptions of different scale surface errors and the effects on EM preformation, and the surface error will be expressed in the optical pathlength difference (OPD) in general
Summary
With the development of radio astronomy and deep space exploration, the requirements for the resolution and sensitivity of the reflector antenna are raised. Lian et al [13] developed a multiobjective optimization model to analyze the effects of surface errors’ nonuniformity along the radius on the reflector’s radiation characteristic and discussed that for the same RMS of errors for the whole reflector, different distributions along the radius result in different gain losses and sidelobe levels. These works consider only one type of error distribution, such as the variations in radial or azimuthal directions, and they cannot represent all situations that influence of the arbitrary error distributions. Based on many numerical simulations, the relationships between a typical EMP and the aberration coefficients are
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
