平板裂缝天线表面误差对其电性能的影响机理研究

The planar slot antennas is the preferred antenna from used in the airborne fire control radar due to the excellent structure and electric performance, such as compact structure, light weight, high gain and low side-lobe. The structure of the planar slot antennas is easy to be deformed because of long-time working in the environment of strong vibration and high temperature difference. Therefore, the cavity surface error of the antennas becomes the main bottleneck to the performance improvement. This project will discuss the modeling of the surface error and the influence mechanism to the antenna performance of radiation waveguide and radiation array. It is aiming at providing the theoretical foundation and technical support to the effective control of the surface error and new design scheme. Unlike other array antennas, the planar slot antenna consists of radiating and feed structures, and these two are inseparably linked. The specific research contents are as following. The project takes radiation waveguide and radiation array as the research objects, discusses the modeling method of the surface errors and their influence mechanisms to the antenna performance, aiming at providing the theoretical foundation and technical support to the effective control of the surface error and new design scheme. The project is the first to propose two novel modeling methods of the cavity surface error and the surface error based on the electrical properties required. Then, the amplitude and phase errors of the radiating slot caused by the two types of surface errors are obtained, and then the position and direction offset of the radiation slot are studied, and the effect formulas of the surface errors on the antenna electronic performance are deduced. The research is undertaken to present and realize the functional design of the antenna surface, and provides the theoretical foundation and technical support for the antenna entire design. This work has an important theory and practice significances to the antenna optimal designing, properties improving and machining cost reducing. More importantly, the research methods will provide a new way to study the influence mechanism of other structural factors.

平板裂缝天线具有结构紧凑、重量轻、高增益、低副瓣等优异的结构与电气性能，是目前机载火控雷达的首选天线形式。因其辐射单元与馈电网络为一体加工成型，可调性差，又长期工作在强振动、高温差环境，易发生变形，结构误差成为制约其性能提高的主要瓶颈。本项目以天线辐射波导和辐射阵面两类典型结构表面误差为研究对象，对表面误差的建模及影响机理问题进行基础科学研究，旨在为有效控制表面误差、提出新型表面设计方案提供理论指导与方法支持。具体内容：提出基于电性能的表面误差建模方法，分别建立两种结构表面误差数学模型；利用空间坐标转换技术推导辐射缝幅相误差，进而建立表面误差对天线远场方向图影响关系公式；通过建立表面轮廓参数优化模型，实现天线面向电性能的表面功能性设计。本项目的实施对实现天线整体优化设计、提高其性能指标、降低加工成本具有重要理论意义与工程价值，同时也将为其他电子装备结构因素影响机理问题的研究提供思路借鉴。

平板裂缝天线具有结构紧凑、重量轻、高增益、低副瓣等优异的结构与电气性能，是目前机载火控雷达的首选天线形式。因其辐射单元与馈电网络为一体加工成型，可调性差，又长期工作在强振动、高温差环境，易发生变形，结构误差成为制约其性能提高的主要瓶颈。本项目以天线辐射波导和辐射阵面两类典型结构表面误差为研究对象，对表面误差的建模及影响机理问题进行基础科学研究，最终为有效控制表面误差、提出新型表面设计方案提供理论指导与方法支持。具体研究内容：提出基于电性能的表面误差建模方法，建立两种结构表面误差数学模型；利用空间坐标转换技术推导辐射缝幅相误差，进而建立表面误差对天线远场方向图影响关系公式；通过建立表面轮廓参数优化模型，实现天线面向电性能的表面功能性设计。重要结果：经过三年的研究工作，本项目取得了四项重要成果：(1)针对腔体结构表面粗糙度, 建立了表面粗糙度对电性能产生实质影响的机电耦合理论建模; 针对面板结构表面粗糙度特殊的形成机理与分布特点，提出了一种面板广义粗糙度的概念, 对表面粗糙度中三种尺度的误差成分进行有效地分离与重构，建立了表面粗糙度多尺度理论模型; (2)建立了表面粗糙度对平板裂缝阵天线辐射性能的影响关系理论模型;(3)提出了非理想天线机电综合建模仿真分析方法;(4)基于电磁散射理论，实现了非理想表面轮廓的多尺度反演；(5)对三种非理想金属表面的位移电流进行了理论计算。本项目的实施对实现天线整体优化设计、提高其性能指标、降低加工成本具有重要理论意义与工程价值，同时也将为其他电子装备结构因素影响机理问题的研究提供思路借鉴。