Implementation Of Push-broom Scanning Antenna For Satellite Platform

The main contents of this paper are based on the work undertaken by the author in the project of "push-broom" satellite scanning antenna. The"push-broom" scanning antenna technology bears the advantage of being able to automatically form a narrow imaging swath in the observed area as the satellite orbiting the earth, so that much scanning time can be saved.Based on the basic principle of "push-broom" satellite scanning antenna, this paper set up the mathematical model with detailed derivations and formulae. This paper mainly focuses on the scanning mechanism of "push-broom" satellite antenna with an example with center frequency of 140GHz, which can be applied to many fields, such as meteorological satellite, ocean cloud monitoring and astronomical observation. The antenna system consists of two parts: (1) Paraboloidal surface obtained by rotation of a parabola; (2) Multiple feeds working at 140GHz, in which the simulated radiation pattern in the shows an edge taper of -16dB at 15°. The feed is placed at the rotating focal point with the same spacing between adjacent feeds, with the distance from each feed to the rotating paraboloid being equal. The antenna surface is calculated through the mathematical model, by a MATLAB program to generate data feeding to GRASP. Simulation of electromagnetic performance of the antenna is conducted using GRASP commercial software based on physical optics. At the same time, the software CHAMP is employed to design and simulate different feeds. Finally, the antenna model was designed by SolidWorks engineering software.The main task of this project is to that the imaging pixels of the main polarization between the adjacent feeds reaches a tangent of -20dB. In the course of the study, different parameters were studied so as to make a systematical parametric study.The main results of this paper are as follows: (1) The mathematic modeling of "push-broom" satellite scanning antenna is realized and described in detail by the formulae; (2) A "push-broom" scanning antenna is designed and various parmeters are optimized and analyzed;(3) The physical condition of feed placement was analyzed and the mathematical boundary conditions were established; (4) Designed and parametric study of the feeds; (5) Three-dimensional modeling of the"push-broom" satellite scanning antenna was performed.