Research On Dissimilarity Of Thermal Deformation Of Radar Panel

The unique advantage of active phased array radar(APAR)is that each antenna unit is equipped with a transmit/receive module(TRM),which has many unique advantages such as high reliability and strong functionality.Therefore,it has been paid more and more attention in military aerospace and other fields.Because of this,APAR will produce obvious thermal deformation of array panel due to the change of thermal power consumption of internal devices and external environment temperature,which will result in the decrease of electrical performance such as loss of main lobe gain,increase of side lobe level and pointing angle error.Therefore,it is necessary to study the thermal deformation law of APAR panel to effectively reduce the influence of thermal deformation on electrical performance,which is one of the necessary measures to improve the overall performance of APAR.That is of great significance to improve the radar technology level and enhance the military strength of our country.In order to study the thermal deformation of APAR,this paper takes an APAR experimental prototype as the experimental object.Firstly,the thermal deformation of the panel of the experimental prototype is measured accurately,and then the dissimilarity characteristics of the thermal deformation of the radar panel are analyzed according to the experimental data.The prediction model of the thermal deformation of the radar panel is established through the analysis results and related theoretical algorithm,so as to realize the accurate prediction and compensation of the thermal deformation of the radar panel.The main research work and achievements are summarized as follows:1)According to the principle of thermal power consumption of APAR internal devices,an experimental prototype of APAR is designed to study the thermal deformation of its panel.A vertical CNC machining center is improved to have the function of three coordinate measurement,so as to realize the measurement of thermal deformation of radar array.At the same time,a set of temperature measurement system is designed to realize the synchronous measurement of temperature change and thermal deformation at different positions of radar panel.Considering the influence of the heat source inside the machining center,the heating of the radar model itself and the temperature of the external environment on the accuracy of the coordinate measurement,the thermal error compensation technology for the whole worktable of the machining center is proposed to improve the accurate measurement of the thermal deformation of the radar panel.2)The factors influencing the thermal deformation of radar panel,such as temperature,array size and constraint force,are analyzed.The orthogonal experiment is designed to study the influence of different temperature,dimension and constraint force on the thermal deformation of radar panel,which provides experimental data for the later establishment of radar panel coupling prediction model.In order to obtain the accurate data of the thermal deformation and temperature change in all directions of the radar array,the original measurement results of each batch of experiments are preprocessed and analyzed.3)The dissimilarity of thermal deformation of radar panel is studied.The application of traditional thermal deformation calculation method in finite element analysis and the basic idea of dissimilarity thermal deformation theory are discussed.On this basis,the calculation formula of dissimilar thermal deformation based on the finite element method is proposed,which provides a theoretical basis for the realization of dissimilarity thermal deformation of radar panel.At the same time,the thermal deformation of radar panel under different panel sizes is studied to realize the accurate simulation of the dissimilarity thermal deformation.4)A real-time thermal deformation compensation technology for APAR is proposed.The technology can realize the real-time prediction and compensation of the thermal deformation of the radar panel through the real-time monitoring of the temperature change of the radar panel.On this basis,the coupled model of temperature and constraint force is further established to accurately predict the thermal deformation according to the temperature information and constraint force on panel.The experimental results show that the technology can effectively reduce the influence of thermal deformation of the panel on the electrical performance of the radar,so as to improve the overall performance of the radar,which has important engineering application value.