Congsi Wang

Performance of structurally integrated antennas subjected to dynamical loads

This paper proposes a coupling approach to investigate the effects of dynamic loads on the performance of structurally integrated antenna. In this method, the deformed displacement of radiating elements is determined by using the modal superposition principle of dynamic mechanic equation. Subsequently, the deformed displacement is coupled to the radiated field equation of the antenna array considering the effect of mutual coupling. Finally, an electromechanical coupling model is built by combining the equations from two different disciplines. An iterative solution method is presented to solve the coupling model. Some experimental devices are designed by utilizing a 2.5 GHz structurally integrated antenna, and the results confirm the effectiveness of the coupling model. The validated model is applied to investigate the influences of dynamic loads on the mechanical and electrical performance. The results show that the deformed displacement of radiating elements depends on the structural constraint forms and dynamic load values. Moreover, the greater the deformed displacement of the antenna array surface, the more serious the degradation of the electrical performance. The coupling model is particularly suited to the multidisciplinary analysis and design of structurally integrated antenna.

Panel adjustment error of large reflector antennas considering electromechanical coupling

The errors associated with a segmented primary reflector limit the electrical performance obtainable with those antennas which employ them. It is necessary to derive the effects of panel adjustment error on electtonical performance in order to determine realistic error budgets for such antennas. From the point of electromechanical coupling, an approximate expression for ETM (error transformation matrix) between panel adjustment errors and aperture errors is derived. It is found by numerical simulation that the results may be applied to antennas with realistic panel schemes for prediction of their electrical performance and panel adjustment.

Coupled structural-electromagnetic modeling and analysis of offset reflector antennas

With the development of offset reflector antennas with high performance, the growing demands for high frequency, low sidelobe level and reduced mass have brought structural design and manufacturing process stringent requirements. The coupled structural-electromagnetic problem of offset reflector antennas is studied to find out the prime structural factors which have a great effect on electromagnetic performances, thereby reducing the requirements of minor structural factors effectively. Considering the structural factors such as the reflector surface errors and the feed errors, the coupled structural-electromagnetic model of the offset reflector antenna is discussed and developed by using the aperture field method. The coupled analysis results of the electromagnetic performance of a 2.6-m spaceborne offset antenna with surface thermal distortions caused by solar radiation shows the proposed coupled model is effective and of potential engineering value.

Accurate algorithm for analysis of surface errors in reflector antennas and calculation of gain loss

The distortion of antenna reflector can degrade the antenna performances obviously with the higher work frequency band. A new algorithm used for accurately analyzing the distorted reflectors and computing the axial, normal and radial deviations of distorted surface is developed. The analysis method with simulation values only one third of analysis results of ANSYS software is verified by calculating surface errors and gain losses of a 7.3-m parabolic antenna under different working conditions and comparing the results of accurate algorithm and ANSYS software method. Its application in both large space and ground antennas will greatly improve the design efficiency, reduce cost, and also provide the detailed precise distortion information for electrical designers.

On divided-fitting method of large distorted reflector antennas based Coons surface

Best-fit paraboloid is usually adopted to analyze distorted reflector antennas, which, however, may make the big partial distortion of antenna reflector unnoticeable. Based on the shape of distorted reflector, a new divided-fitting approach is presented combining the hoop trigonometric function fitting and quadratic radial function fitting methods, and adopting Coons surface to fit each divided zone. By this way the reflector can be analyzed and fitted accurately. The derivation of required formulae to calculate the surface deviation is also submitted. The application of the divided-fitting method to analyze a 7.3-m large reflector antenna and the computation of its electrical performances are given in detail with right and useful results.

Implementation and Application of Reflector Antennas Oriented Collaborative Mechatronic Analysis System

A design and analysis software system for reflector antenna structures is described. In the system, antenna designers are only required to input some basic control parameters for obtaining the finite element modeling scheme of typical structure and quickly building the logical finite element modeling. Since the same model data are possessed in the CAD and CAE module, designers can accurately implement the finite element analysis and electromechanical coupling performances analysis at same time, and get correct results and reliable evaluations of mechanical and electrical performances of antennas. The system not only improves the innovative design ability, but also decreases the design default, optimizes product performance, reduces the design and manufacture cost and accelerates the design and manufacture procedure of antennas