second antenna 中文意思是什麼
second antenna
解釋
第二觸角-
In this thesis first the research the sr - df algorithm under the arbitrariness antenna array, which is based on the algorithm of music, second the algorithm has been put into realization on the hardware, so that in the later to embattle the antenna can reference to this thesis
本課題對比較適合的任意形狀天線陣進行了研究，在趨于成熟的music演算法的基礎上，研究任意形狀超分辨測向天線陣通用演算法，然後對該演算法進行硬體的實現。 -
After that it elaborated thesystem design thought of the antenna test turntable automatic test system in thearticle second chapter, including the equipment composition of the antenna testturntable, the technical specification request, the introduction of the electricallycontrolled system and the goniometric system, and elaborated the test systemsoftware platform design proposal
接著在本文的第二章論述了天線測試轉臺自動化測試系統的總體設計思想，包括天線測試轉臺的設備組成、技術指標要求、電控系統和測角系統的介紹，並且論述了測試系統軟體平臺的設計方案。 -
While carrying out the scheme, at first, the basic theory of antenna, array antenna and electromagnetic absorption, the performance parameter of antenna and parabolic antenna are deeply researched. in conformity, the characteristic and calculation of aperture field and near - to - far - field transformation for radiation pattern are detailed analyzed. second, the factors such as, the amount of the antenna elements, mutual coupling between each element, ground and the buildings on earth ' s surface, which affect the performance of array antennas ’ resultant field are stressed discussed
在系統實現過程中，課題首先從天線、陣列天線，以及電磁場計算方法的基本理論著手，分析了天線與拋物面天線的各項性能參數，以及天線的口面場和近-遠區輻射場的特點和計算;進而，更加深入的討論和研究影響天線陣列合成場強的各項因素，包括系統所使用的天線單元個數對陣列合成場的影響、天線單元之間由於互耦造成的影響、傳播過程中地面和/或地面建築物的影響等。 -
The paper includes four sections followed here : the first section studies the modeling of signals of pulse doppler radar seeker, and establishes a radar signal simulation model, including radar emitting signal model, receiving signal model, receiving echo signal model, clutter model, noise model, sum channel directional pattern of antenna model, difference channel directional pattern of antenna model, sheltering model, rcs model, glint noise model, etc. the second section studies signal processing of pulse doppler radar seeker, and establishes radar signal processing mathematical model and data processing mathematical model for simulation, including windowing, doppler filtering, envelope demodulation, pdi, cfar, centering, velocity tracking, angle tracking, a - b filtering, etc. the third section studies the modeling of modified proportion guiding, and establishes guiding model, then dynamic simulation results is provided
論文的主要工作包括四部分：第一部分研究了脈沖多普勒雷達導引頭的信號建模問題，建立了雷達信號模型，主要包括：發射信號模型、接收信號模型、目標回波信號模型、雜波模型、噪聲模型、和差通道天線方向圖模型、遮擋因子模型、接收機噪聲模型、目標雷達截面積統計性模型、目標角閃爍模型等。第二部分研究了脈沖多普勒雷達導引頭的信號處理模式，建立了信號和數據處理模型，主要包括：加窗和多普勒濾波、包絡檢波、檢波后積累、頻域cfar處理、速度定心、速度跟蹤、角跟蹤、 ?濾波等，然後給出了信號處理流程。 -
The conformal microstrip antenna with some unique character has been applied in many fields, especialy on speedy objects. in this paper, an efficient fdtd algorithm is introduced to analyse the microstrip antenna. firstly, the fdtd formula in descartes coordinate system and in cylindrical coordinate system are obtained from the time _ dependent maxwell equations using the yee algorithm in a calculating region where the dielectric parameters are independent of time and space. the choice of the space discretization units and the time discretization interval are discussed which are decided by the accuracy and stability respectively. the shape and setup of the excitation source are discussed too. the excitation source is chosen to be gaussian pulse in shape. secondly, the mur ' s first - order and second - order boundary condition are deduced in cylindrical coordinate system. the methods of transforming radiation fields from near zone to far zone in the frequency domain and in the time domain are presented when fdtd is applied to analyse the characteristics of far zone. finally, three kinds of microstrip antennas are analysed. they are a slot antenna that lies on a plane ground of a microstrip, a slot antenna that lies on a cylindrical ground of a microstrip and a microstrip line _ fed aperture coupled stacked rectangular patch antenna in cylindrical coordinate system
本文從麥克斯韋旋度方程出發，建立了笛卡兒坐標下無源空間中均勻無耗媒質的fdtd基本方程和圓柱坐標下無源空間中均勻無耗媒質的fdtd基本方程，詳細討論了fdtd法計算中時間步長和空間步長的選取原則以及激勵源的類型和設置；推導了mur一階和二階邊界條件在圓柱坐標下的差分格式；給出了在用fdtd法計算天線的遠場輻射特性時必需採用的頻域和時域近場遠場變換技術；最後用fdtd法計算了平面微帶縫隙天線、柱面共形微帶縫隙天線和柱面共形微帶層疊天線的輸入阻抗和遠區輻射場，並分析了天線的一些參數的變化對天線輸入阻抗的影響，得出了一些有用的結論。 -
In the second chapter, a wideband mimo channel model with multiple - tap was integrated according to the angle of departure of the transmitting signal and its spread angle, the angle of arrival of the receiving signal and its spread angle, power azimuth spectra, doppler spectrum and the geometric construction of antenna array both sides of transmit and receive, on the basis of full research on the theories of space - time channel model proposed in the recent literature
第二章在對最近文獻中提出的一些空時通道模型理論進行詳細研究的基礎上，根據發射信號的離開角及其擴展角、接收信號的到達角及其擴展角、功率方位譜、多普勒譜和收發兩端天線的拓撲結構，綜合了一個多抽頭的寬帶mimo通道模型。 -
The distribution network to which dawncom do it best construct include more than 30 branches which have powerful impact all over the country. at the same time, the service antenna is further extended by more than 3000 kernel distributors and over ten thousands second - class distributors
和光所傾力建構的分銷網路共包括30多個在全國各地有相當影響力的分支機構，並通過三千余家核心經銷商和一萬余家次級經銷商進一步延伸了業務觸角。 -
At the point of the second impact there was much debris from the tail fenestron and the antenna of the automatically deployable emergency locator transmitter ( adelt ) installed at the tail of the helicopter, suggesting a touchdown in a nose high attitude
在第二次撞擊地點則發現許多尾旋葉及安裝于機尾的自動緊急定位發射器的碎片，顯示直升機著地時機頭朝上。 -
The research content of this dissertation include two main part, the first is the design and analysis of deployable antenna on satellites and the second is the analysis of cable - membrane structure & the development of cad system for this kind of structure
本文主要研究內容可分為兩大部分，第一部分為空間可展天線結構的設計與分析；第二部分為索膜結構分析及cad軟體的開發研製。 -
Second, both the optimized beamforrnkig for antenna array and constant module algorithm are explored. we deeply study the performance of adaptive array under wireless multi - path environment
其次，分析了天線陣列最優波束形成技術和恆模演算法，深入研究了無線多徑環境下自適應陣列的性能。
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