Airborne Radome Analysis And Design Of The Study

Due to the limitations of conventional ray tracing method in practical antanna-radome system computation and design, this dissertation focus mainly on the more flexible and efficient ways in radome analysis and therefore uses the ray tracing and surface integration method. Then two directly broadening of ray tracing application are discussed in this paper. One is a modifying ray tracing technique for equiangu.lar spiral antenna in radome, which is a kind of small antenna and not fit for the conventional ray tracing method. This technique is presented to calculate the far field around the equiangular spiral antenna using the formula according to the former theoretical result. And the other is the general geometrical modeling of the arbitrary radome surface by using the Non-Uniform Rational B-Splme (NURBS) surfaces of Computer Aided Geometric Design (CAGD). With the introduction of NURBS the curves and surface of radome can be accurately defined and the following computation, which includes the integration on the surface for the antenna radiation characteristics in radome, can reach high precision, accordingly. In the radome design procedures, which are utilized to the engineering applications, the optimal design seems more and more necessary and desirable. This dissertation also presents an optimization technique based on the ray tracing method and the surface integration above the local planar slabs of radome. To obtain the maximum transmission coefficient, the minimum boresight error and cross-polarization level, a double-optimization model is constructed using the mini-max principle and is solved by the complex method. The utility results of this optimization algorithm are illustrated and show good characteristics in this paper.