本文選題：反射面型脈沖輻射天線　切入點：共形時域有限差分法　出處：《西南交通大學》2014年博士論文

【摘要】：反射面型脈沖輻射天線能很好地定向輻射電磁脈沖,它具有主瓣波束窄,作用距離遠,空間、時間分辨率高等優(yōu)點,在定向能武器、目標探測、成像等領域都有著廣泛的應用。由于反射面型脈沖輻射天線所輻射的電磁脈沖其頻譜成分豐富,作為饋源的超寬帶天線將無法擁有固定的相位中心,這是反射面型脈沖輻射天線設計中的一大難點。為了使反射面型脈沖輻射天線能向遠場輻射高峰值、高保真度的沖擊脈沖,提高饋源的能量輻射效率,通常依賴數(shù)值仿真方法和優(yōu)化算法對反射而型脈沖輻射天線進行優(yōu)化設計。然而,該類天線為電大尺寸天線,反復數(shù)值模擬計算,將占用大量計算資源,優(yōu)化速度緩慢。因此,本文致力于尋求加快反射面型脈沖輻射天線優(yōu)化設計速度的普適方法。時域電磁場計算方法可較為直接、直觀地求解超寬譜電磁脈沖問題。其中,共形時域有限差分法(Conformal Finite Difference Time Domain, CFDTD)在處理帶有曲面結構的電磁目標仿真問題時,具有獨特的優(yōu)勢,適合于反射面型脈沖輻射天線的研究。但是,由于仿真目標形式多樣,它們的共形網格建模往往十分繁瑣。為此,本文將研究滿足三維CFDTD方法求解的電磁目標自動幾何建模方法。同時,優(yōu)化算法已經普遍應用于各類天線的優(yōu)化設計之中。在優(yōu)化過程中,反復調用計算天線參數(shù)的正問題的仿真程序是優(yōu)化設計中最為耗時且占用計算資源的。為此,本文引入代理模型,研究減少調用數(shù)值仿真程序次數(shù)的全局優(yōu)化算法,以減少天線的優(yōu)化設計時間,提高優(yōu)化效率。綜上所述,本文主要工作如下：第一,基于“切片-線掃描”法,實現(xiàn)多材料復雜實體組合的共形網格自動建模,適用于CFDTD求解,具備很好的通用性。該方法以三角面元文件為輸入數(shù)據(jù),通過對“切片-線掃描”法的改進,以及對網格相對面積的修正,可以快速確定各網格棱邊和面上的等效實體信息,實現(xiàn)目標模型的高效共形網格重構。將該方法應用于一個對開口漸變曲線較為敏感的對跖式漸變開槽天線的幾何建模,其數(shù)值模擬結果與測試結果吻合很好,表明該共形網格自動剖分方法的正確性和有效性。第二,研究了Taguchi優(yōu)化方法與BP (Back Propagation)神經網絡相結合的方法,稱作BP-based Taguchi算法。通過函數(shù)測試,分析優(yōu)化維數(shù)增加,以及優(yōu)化進程的推進,對BP神經網絡預測誤差的影響,認為,有必要在BP神經網絡使用一定代數(shù)后,重新訓練BP神經網絡,以確保BP神經網絡的預測精度滿足進一步的尋優(yōu)要求。分別對三元非規(guī)則三角天線陣(3維)、十元非規(guī)則三角天線陣(6維)、四元非規(guī)則矩形邊界天線陣(8維)和圓弧式變形TEM喇叭天線單元(13維)進行了優(yōu)化。優(yōu)化結果表明,當優(yōu)化維數(shù)低于8維時,相較于Taguchi優(yōu)化方法,采用BP-based Taguchi算法可有效減少調用數(shù)值仿真程序的次數(shù)。第三,實現(xiàn)了基于混合代理模型的高效全局優(yōu)化算法(Hybrid-Surrogate-Model-based Efficient Global Optimization Algorithm, HSM-based EGO)。 HSM-based EGO算法以Kriging模型和RBF (Radial Basis Function)神經網絡為混合代理模型,分別根據(jù)最大期望改進、最低抽樣密度和當前局部最優(yōu)來獲取新抽樣點,每代只需調用數(shù)值仿真程序3次,且與優(yōu)化維數(shù)無關。將HSM-based EGO算法應用于一個12維的復合振子天線優(yōu)化設計,并與EGO算法和微分進化策略(Differential Evolution Strategy, DES)算法的優(yōu)化結果進行了對比,它們的收斂曲線表明了這種采用混合代理模型的優(yōu)化算法不僅具有較快的收斂速度,也有良好的全局搜索能力,適用于高維優(yōu)化問題的全局尋優(yōu)。第四,當饋源已確定,且為對稱結構時,本文根據(jù)反射面型脈沖輻射天線的基本特性,提出了以饋源軸向輻射脈沖的峰值時刻瞬態(tài)方向圖為參考,以確定超寬帶饋源時域近似輻射中心與輻照角的方法,從而實現(xiàn)反射面型脈沖輻射天線的快速設計,使反射面天線系統(tǒng)在軸向的輻射增益最強。將該設計方法分別應用于前饋式反射面型脈沖輻射天線(以阻抗?jié)u變式變形TEM喇叭為饋源)、卡塞格倫型脈沖輻射天線(以圓弧式變形TEM喇叭為饋源)和單偏置反射面型脈沖輻射天線(以2×2同軸指數(shù)漸變式變形TEM喇叭天線陣為饋源)的快速設計,并將它們的設計結果與采用掃參或優(yōu)化算法優(yōu)化設計的結果進行對比,各方法的設計結果皆非常接近,表明了這種時域快速設計方法的有效性。第五,本文利用帶橢球反射面的近場聚焦天線具有天然近似輻射中心的結構特點,設計了一款遠場輻射性能良好的準格里高利型脈沖輻射天線。以脈沖寬度分別為200ps和330ps的高斯脈沖激勵該天線,該天線饋源的瞬時輻照角寬度符合理論設計要求,當拋物反射面口面直徑為1.5m時,天線對應的3dB波束寬度皆小于±3°(H面)和±5°(E面),表明該天線適合于亞納秒級電磁脈沖的輻射,且具有良好的定向性。
[Abstract]:Reflective pulse radiation antenna can well directional radiation of electromagnetic pulse, it has narrow beam main lobe, the role of distance, space time, high resolution, energy weapons, in the direction of target detection, imaging and other fields are widely used. Because the reflective pulse radiation antenna radiation of the electromagnetic spectrum rich composition as the pulse ultra wideband antenna phase center will not have fixed, this is one of the difficulties of reflective pulse radiation antenna design. In order to make reflective pulse radiation antenna to the far field radiation peak value, high fidelity impulse, improve the energy radiation efficiency of the feed and often rely on the method of numerical simulation and optimization algorithm for reflection type pulse radiation antenna is optimized. However, this kind of antenna is electrically large antenna, repeated numerical simulation, will occupy a large amount of computing resources, and The speed is slow. Therefore, this paper is devoted to seeking to speed up the reflective pulse radiation antenna optimization design speed universal method. The time-domain method can be more direct and intuitive solution of ultra wide spectrum electromagnetic pulse. The conformal FDTD method (Conformal Finite Difference Time Domain, CFDTD) in the problem of electromagnetic target simulation with curved structure, has unique advantages, suitable for the study of pulse radiation antenna on the reflection plane. However, the simulation of target forms, their conformal mesh modeling are often very complicated. Therefore, this paper will study the target to meet the electromagnetic automatic modeling method for solving the three-dimensional CFDTD method. At the same time, optimization the algorithm has been widely used in various types of antennas. In the optimization process, the simulation program is called repeated calculation of the antenna parameters are optimized. In the most time-consuming and consumes computing resources. Therefore, this paper introduces the proxy model to reduce the global optimization of numerical simulation program the number of calls, time optimization design to reduce the antenna, improve the optimization efficiency. To sum up, the main work is as follows: first, "cut line scanning method based on multi material complex conformal mesh modeling combinations, suitable for the solution of CFDTD, has good versatility. This method takes the triangular element file as input data, through the improvement of the" cut line scanning method, and modified the relative area of the grid, can quickly determine the grid edge and on the surface of the equivalent the entity information, to achieve the goal of model, conformal mesh reconstruction. This method is applied to a more sensitive to the gradient curve of plantar opening type tapered slot antenna geometric modeling, the numerical simulation results and The test results are in good agreement, show the correctness and effectiveness of the conformal mesh generation method. Second, research on Taguchi optimization method and the BP (Back Propagation) method combined with neural network, called BP-based Taguchi algorithm. Through the function test, analysis and optimization of dimension increase, and promote the optimization of the process, think the BP neural network prediction error, and it is necessary to use some algebra in BP neural network, to train the BP neural network, to ensure that the prediction accuracy of BP neural network to meet the requirements of further optimization of three yuan respectively. The irregular triangular array (3 dimension), ten yuan (non regular triangle array 6 dimension), four yuan of irregular rectangle array (8 dimension) and arc deformation of TEM horn antenna unit (13 dimension) is optimized. The optimization results show that when the optimal dimension less than 8 dimensions when compared to the Taguchi optimization method, using BP-based The Taguchi algorithm can effectively reduce the number of calls to the numerical simulation program. Third, to achieve an efficient global optimization algorithm based on hybrid agent model (Hybrid-Surrogate-Model-based Efficient Global Optimization Algorithm, HSM-based EGO). HSM-based EGO algorithm based on the Kriging model and the RBF (Radial Basis Function) neural network mixed agent model, respectively according to the maximum expected improvement, minimum sampling the current density and the local optimum to obtain new sampling points, each generation can only call a numerical simulation program for 3 times, and has nothing to do with the optimal dimension. HSM-based EGO algorithm is applied to a 12 dimensional composite oscillator antenna design and optimization, and EGO algorithm and differential evolution strategy (Differential Evolution, Strategy, DES) algorithm optimization the results were compared and their convergence curves show that the hybrid optimization algorithm model not only has Fast convergence speed, also has good global search capability, suitable for high dimensional global optimization problem. Fourth, when the feed has been determined, and the symmetrical structure, according to the basic characteristics of reflective pulse radiation antenna, put forward to the peak time of transient axial direction feed radiation pulse figure for reference. To determine the ultra wideband feed time domain approximation method for radiation center and irradiation angle, so as to realize the rapid design of reflective pulse radiation antenna, the reflector antenna in the strongest radiation gain axial. The design methods are applied to feedforward reflective pulse radiation antenna (with the impedance tapered TEM horn feed for deformation). Casey Glenn type pulse radiation antenna (with arc type TEM horn feed for deformation) and single offset reflective pulse radiation antenna (2 x 2 coaxial progressive deformation index TEM horn antenna array For the fast feed) design, and the design results and they used to sweep or optimization algorithm to optimize the design by comparing the results of each method design results are very close to show the effectiveness of the fast design method of the time domain. Fifth, the structure with reflecting surface ellipsoid near field focusing antenna has a natural approximation the radiation center, designed a good performance of the quasi far field radiation Gregory type pulse radiation antenna. The pulse width was 200ps and 330ps excitation of the antenna Gauss pulse, the transient radiation antenna angle width meets the requirements of theoretical design, when the parabolic reflector aperture diameter is 1.5m, the 3dB beam width of antenna the corresponding is less than 3 degree (H) and + 5 degrees (E surface), show that the antenna is suitable for sub nanosecond pulsed electromagnetic radiation, and has good directivity.

【學位授予單位】：西南交通大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TN820

【參考文獻】

相關期刊論文 前10條

1 黃娜斌;江波;張志蓮;李翱;;Taguchi DOE實驗設計法注射成型工藝參數(shù)優(yōu)化[J];工程塑料應用;2007年06期

2 董躍;田雨波;;基于PSO-BP算法的微帶天線諧振頻率神經網絡建模[J];中國傳媒大學學報(自然科學版);2009年02期

3 鄒愛民;程德福;王可可;趙飛;;隧道地質超前預報探地雷達脈沖源的設計[J];吉林大學學報(信息科學版);2008年05期

4 朱湘琴;王建國;朱金輝;;FDTD-TDEEC混合法計算拋物面天線遠區(qū)輻射場[J];電波科學學報;2008年02期

5 覃延明;廖成;衛(wèi)濤;劉昆;;超寬帶TEM喇叭天線陣列的微遺傳算法優(yōu)化[J];電波科學學報;2008年02期

6 郭晨;張安學;吳輝;蔣延生;汪文秉;;高功率超寬帶雙饋源拋物面天線設計與仿真[J];電波科學學報;2008年04期

7 姚陳果;龍再全;孫才新;米彥;李成祥;;生物醫(yī)用沖激脈沖輻射聚焦天線的設計與優(yōu)化[J];電工技術學報;2011年02期

8 張秋菊;王秉中;;時域有限差分電磁仿真的網格自動剖分[J];電子科技大學學報;2007年01期

9 姜正茂;楊建宇;李良超;;BP神經網絡天線方向圖獲取方法研究[J];電子科技大學學報;2010年01期

10 吳毅強;鄧淼;廖昆明;曾永安;周輝林;;一種新型超寬帶單極子天線設計與仿真[J];電子元件與材料;2012年07期

相關會議論文 前1條

1 鄭軒;廖成;常雷;方劍;;基于微分進化策略的超寬帶微帶天線自動優(yōu)化設計[A];2009年全國天線年會論文集（上）[C];2009年

相關博士學位論文 前2條

1 吳鋒濤;超寬帶天線頻域和時域算法理論與應用研究[D];國防科學技術大學;2007年

2 覃延明;基于進化算法的超寬帶TEM喇叭天線陣列優(yōu)化研究[D];西南交通大學;2009年

相關碩士學位論文 前4條

1 吳曉華;時域天線及其陣列研究[D];電子科技大學;2011年

2 黎佳;超寬帶反射面天線系統(tǒng)輻射特性研究[D];中國工程物理研究院;2011年

3 吳錚;基于遺傳算法和神經網絡的天線優(yōu)化設計研究[D];南京航空航天大學;2008年

4 謝飛;高功率電磁脈沖輻射技術研究[D];哈爾濱工業(yè)大學;2009年

，

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