本文選題：星載陣列天線 + 微帶天線�。� 參考：《西安電子科技大學》2014年碩士論文

【摘要】：星載陣列天線作為空間通信、電子偵察、導航、環(huán)境監(jiān)測等衛(wèi)星系統(tǒng)的“眼睛”和“耳朵”,通過空間可展開結(jié)構(gòu)實現(xiàn)較大的物理口徑,同時克服了傳統(tǒng)機械掃描天線的諸多缺點,已成為宇航領(lǐng)域的關(guān)鍵裝備之一,具有重要的應(yīng)用價值和廣闊的發(fā)展前景。作為星載陣列天線主要形式之一的星載微帶陣列天線,受太空惡劣溫度環(huán)境的影響,微帶陣列天線易發(fā)生結(jié)構(gòu)熱變形。對于低剖面的微帶天線而言,結(jié)構(gòu)熱變形不僅包括天線單元位置的改變,同時天線單元自身結(jié)構(gòu)也將發(fā)生變化。為了分析星載微帶陣列天線結(jié)構(gòu)熱變形對天線電性能的影響,本文從機電耦合的角度進行研究,主要包括以下內(nèi)容:首先,闡述星載陣列天線的結(jié)構(gòu)特點和七項關(guān)鍵結(jié)構(gòu)技術(shù),針對典型的X波段、中心頻率為10GHz的星載微帶天線進行結(jié)構(gòu)建模與優(yōu)化設(shè)計,得到了一副回波損耗大于20dB的星載微帶天線單元。然后,針對天線單元,從機電耦合的角度出發(fā),以微帶天線單元輻射特性為基礎(chǔ),建立了基于自身結(jié)構(gòu)改變(表面彎曲)的微帶天線單元機電耦合模型。通過與電磁軟件HFSS仿真結(jié)果對比分析,確定其適用范圍:對于X波段微帶天線單元發(fā)生彎曲變形,當變形對應(yīng)圓心角小于40°時,相對誤差滿足工程誤差小于5%的要求。利用微帶天線單元的機電耦合模型分析結(jié)構(gòu)熱變形對天線電性能的影響,主要表現(xiàn)為:高溫環(huán)境下(100℃~120℃),隨著溫度的升高,熱變形量增大,天線電性能逐漸降低,增益最大降低0.21dB;低溫環(huán)境下(-140℃~-160℃),隨著溫度的降低,熱變形量增大,天線電性能逐漸降低,增益最大降低0.42dB。最后,針對陣列天線,在微帶天線單元機電耦合模型的基礎(chǔ)上,通過電磁疊加原理,建立了包括天線單元自身結(jié)構(gòu)改變(表面彎曲)、位置偏移和指向偏轉(zhuǎn)的機電耦合模型,并以X波段1×5的線陣為例,分別針對線陣結(jié)構(gòu)無變形和彎曲變形(包括單元表面彎曲、位置變化和指向偏轉(zhuǎn))兩種情況與HFSS軟件進行對比驗證,驗證結(jié)果表明機電耦合模型計算結(jié)果與電磁軟件仿真結(jié)果的相對誤差滿足工程誤差小于5%的要求。利用微帶陣列天線機電耦合模型分析結(jié)構(gòu)熱變形對天線電性能的影響。結(jié)構(gòu)熱變形導致天線電性能降低,主要表現(xiàn)為:高溫120℃環(huán)境下,增益降低0.27dB,副瓣抬高2.07dB,波束指向偏轉(zhuǎn)0.03°;低溫-160℃環(huán)境下,增益降低0.72dB,副瓣抬高3.98dB,波束指向偏轉(zhuǎn)0.1°;50℃熱梯度環(huán)境下(20℃~70℃),增益降低0.18dB,副瓣抬高1.17dB,波束指向不變。
[Abstract]:As the "eyes" and "ears" of satellite systems such as space communication, electronic reconnaissance, navigation and environmental monitoring, space-borne array antennas can achieve large physical caliber through space deployable structures. At the same time, it overcomes many shortcomings of the traditional mechanical scanning antenna, and has become one of the key equipment in the field of space navigation, which has important application value and broad development prospect. Spaceborne microstrip array antenna, as one of the main forms of space-borne array antenna, is prone to structural thermal deformation due to the bad temperature environment in space. For the microstrip antenna with low profile, the thermal deformation of the structure includes not only the change of the position of the antenna element, but also the change of the structure of the antenna unit itself. In order to analyze the effect of thermal deformation on the electrical properties of space-borne microstrip array antenna structure, the main contents of this paper are as follows: firstly, the structural characteristics and seven key structural technologies of space-borne microstrip array antenna are described. A typical space-borne microstrip antenna with X-band and 10GHz center frequency is modeled and optimized. A space-borne microstrip antenna unit whose echo loss is greater than 20dB is obtained. Then, based on the radiation characteristics of the microstrip antenna unit, the electromechanical coupling model of the microstrip antenna unit based on its structure change (surface bending) is established from the point of view of electromechanical coupling. By comparing with the simulation results of electromagnetic software HFSS, the applicable range is determined: for X-band microstrip antenna elements, when the corresponding center angle of deformation is less than 40 擄, the relative error can meet the requirement of less than 5% of engineering error. The electromechanical coupling model of microstrip antenna elements is used to analyze the effect of thermal deformation on the electrical properties of the antenna. The main performance of the antenna is as follows: at high temperature, 100 鈩，

本文編號：1780374