射電天文天線 的英文怎麼說
中文拼音 [shèdiàntiānwéntiānxiàn]
射電天文天線
英文
radio astronomy antenna- 射 : Ⅰ動詞1 (用推力或彈力送出) shoot; fire 2 (液體受到壓力迅速擠出) discharge in a jet 3 (放出) ...
- 電 : Ⅰ名詞1 (有電荷存在和電荷變化的現象) electricity 2 (電報) telegram; cable Ⅱ動詞1 (觸電) give...
- 文 : Ⅰ名詞1 (字) character; script; writing 2 (文字) language 3 (文章) literary composition; wri...
- 線 : 名詞1 (用絲、棉、金屬等製成的細長的東西) thread; string; wire 2 [數學] (一個點任意移動所構成的...
-
Radio astronomy today is armed with the largest antennas in the world.
射電天文學擁有世界上最大的天線。Since complicated differential and integral operations were involved in the kernel of the integral equation, we simplified the equation and got the nakano equation. as instances, the planar archimedean spiral antenna, the planar equiangular spiral antenna, the monofilar helical antenna, the conical helical antenna with fixed ascending angle and the conical equiangular - spiral antenna were analyzed through the moment method. all of the results matched fairly well with the references and experiment results
這種方法的積分方程的積分核里含有復雜的微積分運算,為了簡化計算,本文在推廣的海倫積分方程的基礎上,對方程進行了簡化,推導了nakano方程,並以平面阿基米德螺旋天線,平面等角螺旋天線,軸向模圓柱螺旋天線,具有固定升角的圓錐螺旋天線和圓錐等角螺旋天線為例,用矩量法求解了天線上的電流分佈,研究了螺旋天線輻射的寬頻帶特性,所得的結果均與參考文獻吻合很好。Above this 34 - m antenna, called dss - 13, is one of those large dishes of the deep space network in goldstone, california and is primarily used for receiving echoes reflected from asteroids when they are beamed by groundbased radio signals
圖上這座口徑34米的天線,編號dss - 13 ,隸屬美國加州的深空網路。當天文學家從地面向小行星發射無線電波時,小行星會把部分電波反射回地球,並由dss - 13所接收。Above ) this 34 - m antenna, called dss - 13, is one of those large dishes of the deep space network in goldstone, california and is primarily used for receiving echoes reflected from asteroids when they are beamed by groundbased radio signals
(圖上)這座口徑34米的天線,編號dss - 13 ,隸屬美國加州的深空網路。當天文學家從地面向小行星發射無線電波時,小行星會把部分電波反射回地球,並由dss - 13所接收。We present a calculation program in this paper, based on the physical optical theory ( po ) theary to predict bse and bses for a conical type of radome. the po theory is used to determine the ficticius currents electrical and magnetic on the inner face of the radome, which is illuminated directly by the radar antenna, and then use the transmission matrix mothod to determine the outer surface ficticion currents, the radiated from the antenna through radome is considered as the radiation field of these ficticion current
本文提出了一種基於物理光學理論預測正圓錐天線罩瞄準誤差及瞄準誤差斜率的計算程序。首先,雷達天線照射到天線罩內壁,應用物理光學法求出內壁等效的電流和磁流,其次,根據傳輸矩陣理論求出外壁等效電流和磁流,天線通過天線罩的遠區場即可認為是外壁等效電、磁流產生的場。A patch antenna with air holes in the substrate has been designed. the finite - difference time - domain ( fdtd ) method together with the perfectly matched layer ( pml ) boundary treatment has been used to study the performance of the antenna. it is shown that the surface waves are significiently suppressed, the frequency bandwidth is improved, the sidelobe levels are reduced and consequently the gain in the forward direction is improved by 14 db ( about 4 db higher than the value reported previously )
設計了一種基底鉆周期圓孔結構的電磁(光子)晶體貼片天線,用fdtd方法並結合pml吸收邊界條件對該天線進行了研究,結果表明本文所設計的基底鉆孔型電磁晶體貼片天線取得了多方面的性能改善,與普通天線相比,基底中的表面波受到很大抑制,天線的帶寬增加,遠場方向圖上天線的旁瓣和背瓣被明顯削弱,向前輻射的增益由原來的12db增加到26db ,增加了14db ,比文獻上報道的gonzalo等人的研究結果提高了4db 。Lastly, a kind structure of vivaldi antenna and new style feed system are presented and the effects of vivaldi antenna ’ s various parameters on radiation performances are discussed in detail though theoretical analysis and optimization design. accroding to the result of design, the experiment of prototype is fabricated
然後,本文提出了一種vivaldi天線結構及其新型的饋電系統,通過理論分析、模擬優化設計,詳細討論了vivaldi天線的各種參數對輻射性能的影響。根據設計結果,完成了實驗樣機的製作。The first serious attempt to listen for possible radio signals from other civilizations was carried out at the national radio astronomy observatory in greenbank, west virginia, in 1959 and 1960
第一次系列地收聽來自其他文明社會的可能的無線電信號,於1959年和1960年在位於西弗吉尼亞的格林邦克的國家射電天文臺里進行。This technique combines the edge - based finite - element method with physical optics ( po ) and physical theory of diffraction ( ptd ). the hybrid technique is applied to compute the scattering fields from the electrically large bodies with cracks and cavities on their surfaces. it is also used to analyze the scattering characteristics of microstrip antennas residing in a cavity mounted on metal objects with finite sizes
本文採用edge - basedfem為基本方法,結合物理光學法( po ) 、物理繞射理論( ptd ) 、邊界積分方程( bi ) 、區域分解技術( ddm )和完全匹配層( pml )吸收邊界條件等求解方法構成的混合方法,對電磁散射和輻射問題進行了研究,主要包括以下內容:提出了一種edge - basedfem與物理光學方法和物理繞射理論相結合的混合方法? fem po - ptd方法,並將該混合方法應用於帶有腔體或槽縫的電大尺寸導體目標的電磁散射特性分析和位於有限導體目標上的背腔式微帶貼片天線的電磁散射特性分析。The performance of the pbg antenna using the new pbg cover together with a pbg substrate is studied by the fdtd method together with the pml boundary treatment. the numerical results show that a more focused beam radiated in the broadside direction is achieved. the gain of the pbg patch antenna in the forward direction is improved by about 6 db. the radiation directivity is improved significantly and reaches 11. 5 db, which is 0. 4 db less than the maximum value that is allowed physically for this size of the antenna ( this difference is about 4. 1 db less than the difference achieved by thevenot et al.,
用fdtd方法並結合pml吸收邊界條件,我們對加了這種新的覆層結構並且基底鉆孔的復合結構電磁(光子)晶體貼片天線的性能進行了研究,結果證明加了這種新的電磁晶體覆層結構以後,天線的波束收攏很多,並且向前輻射的增益大大提高,與普通天線相比,天線的e面和h面方向圖上向前輻射的增益均提高了約6db ,另外,該復合結構天線的方向性系數達到了11 . 5浙江大學博士學位論文db ,與該物理尺寸天線的方向性系數的理論極限值( 11 . 9db )相差0 . 4db ,該差值比thevenot等人設計的電磁晶體覆層天線的相應差值減少了約4 . 1db ,比qiu等人設計的電磁晶體天線的相應差值減少了約1This dissertation is focused on the radiation problems of various kinds of wire antennas mounted on the complex - shaped pec platform and the scattering problems of complex - shaped electrically - large pec targets based on the theory of method of moments
本文主要應用基於電場積分方程( efie )的矩量法( mom )研究復雜形狀的金屬載體上多種線天線的電磁輻射問題以及復雜形狀金屬目標的電磁散射問題。Abstract : making use of the propagation property of the electomagnetic wave, the authors made a further discussion on the directional characteristics of the radiation elecromagnetic waves from elements antenna, symmetric whip and antenna array, and analysed the effects of various factors on the directional characteristics
文摘:利用電磁波的傳播特點,對元天線、對稱振子及其天線陣輻射電磁波的方向性做進一步的探討,並分析各因素對其輻射方向性的影響。In this dissertation, the calculation of the electromagnetic radiation and the electric magnetic compatibility of the conducting body with the wire antenna attachment is discussed, which is based on the classic moment method technology while using the visual c + + as the programming environment and the programming tool
本文以經典的矩量法為理論基礎,以microsoftvisualc + +為主要編程環境和編程工具,計算插有細天線的金屬導體的電磁輻射和電磁兼容特性。After the discussion of the numerical simulation method based on the fdtd method and the pml technique, the motions of the charges and the electrical field lines were first employed to describe the radiation procedures of the pulse electromagnetic waves. then the causes of how the charges are accelerated and how the motion status of the charges are maintained were further studied from the angle of interaction of charge and field. after these analyses, it was pointed out that the pulse radiation is due to the suddenly occurred time - varying electrical field ( displacement current ) in the open space. this view was further evidenced by two examples : one is the partly resistance loaded antenna, the other is the partly curved antenna. the radiation procedures of the pulse electromagnetic waves of many different situations were simulated throughout this paper with the contours and waveforms of electric field given. these figures are very helpful to the understanding of the radiation mechanism of the pulse electromagnetic waves
在討論了基於時域有限差分法和完全匹配層技術的數值模擬方法之後,首先從運動電荷和電力線的角度直觀地描述了脈沖電磁波的輻射過程,然後進一步從場與電荷相互作用的角度分析了天線上電荷是如何被加速以及如何維持其運動狀態的,指出了開放空間中突然出現的時變電場(位移電流)是脈沖電磁波輻射的根本原因.文中還對局部電阻加載的天線和局部彎曲的天線進行了研究,以進一步說明上述觀點.對多種情況下的脈沖輻射過程進行了數值模擬,並給出了電場的等高線和空間波形圖,這些圖形對理解脈沖電磁波的輻射機理非常有益In this dissertation, the radiation problems of wire antenna mounted on the arbitrary shaped conducting platform and the scattering problems of arbitrary shaped conducting objects are analyzed using impedance matrix interpolation with the moment method
本文應用矩量法結合阻抗矩陣插值技術,快速有效地求解實際工程問題中常見的任意形狀金屬目標的電磁散射問題及金屬載體上線天線的電磁輻射問題。In the following section, the thesis demonstrated the robustness of the proposed method in the computation of radiated electromagnetic fields of switched mode power supplies by means of a numerical study on the electromagnetic fields of an electric dipole antenna
應用本文開發基於pml吸收邊界條件三維時域有限差分計算軟體,計算了電偶極子天線的三維輻射電磁場,並將計算結果與解析解進行了對比分析,驗證了時域有限差分法計算高頻開關電源輻射電磁干擾的有效性。This thesis discussed the affection of all kinds of components contingency and the components " position in the line and other factors on the evaluation of load point reliability index. this thesis adopts a integrative method to deal with simple or complex distribution network with the system ' s practical operation characteristics and the results of the example reveal that it is feasible. the key to study the economics of power system reliability is outage costs
在定量評估負荷點或系統可靠性指標的研究中,本文較全面地分析了各元件故障和元件在線路中的位置以及計劃檢修、臨時停電、天氣因素、負荷轉移等因素對估算負荷點可靠性指標的影響;研究了現有的可靠性評估模型,結合城市電網的實際運行特點,採用一種綜合的方法估算輻射型電網的可靠性指標,算例結果表明它是有效可行的。In this paper, the crosstalk and radiation of multiple - core cable is analyzed according as the multiconductor transmission line, two ports network and antenna theory. firstly the fundamental theories are presented
本文主要依據多導體傳輸線理論、二埠網路理論和天線理論對多芯電纜的耦合泄漏和輻射發射進行了較為詳細的分析討論。Astronomers expect it to continue to spin down, eventually reaching a point when its rotation will be too slow to power the radio pulses
天文學家預期它的自轉會繼續變慢,直到它慢得不足以發射無線電脈沖為止。Radio waves emitted by neutral hydrogen in the universe are detectable and the frequency is around 1. 42 ghz. in hong kong, this frequency is protected by international treaties and reserved for radio astronomical observation
人們能夠測量在宇宙內由中性氫產生的無線電波,頻率約在1 . 42 ghz ,在香港,這段頻道是受到國際公約保護,留作射電天文觀測之用。分享友人