broadband dipole 中文意思是什麼
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A large planar microphone array, which consists of 111 microphones, was successfully applied to obtain a two - dimensional mapping of the sound sources on a landing aircraft. the focus of study in this paper is on the landing gear noise source. the spectra, directivities and sound pressure levels of flap side - edge noise of 7 narrow - board commercial aircraft and 7 wide - board commercial aircraft are presented. it is found that the landing gear noise spectrum is broadband with some single tones in some cases. the directivity of the total sound pressure level of a landing gear noise resembles that of a horizontal dipole. the level differences between the various aircraft landing gears are larger than those expected from the airspeed differences. it is thus expected that the louder noise emission of the landing gears can be reduced by redesigning
應用由111個傳聲器組成的平面傳聲器陣列對當前流行的民用客機進場著陸過程中的機體噪聲源進行了實驗測量，本文對七架窄體客機和七架寬體客機的起落架噪聲進行了分析，得到了起落架噪聲的頻譜特性、指向特性和聲級變化.研究發現，起落架噪聲的頻譜是由寬頻隨機噪聲與一些較為明顯的單音噪聲源組成，起落架噪聲的指向性類似於一個水平放置的偶極子.不同飛機起落架噪聲的聲級相差較大，這說明可以通過重新結構設計降低起落架噪聲。 -
Abstract : a large planar microphone array, which consists of 111 microphones, was successfully applied to obtain a two - dimensional mapping of the sound sources on a landing aircraft. the focus of study in this paper is on the landing gear noise source. the spectra, directivities and sound pressure levels of flap side - edge noise of 7 narrow - board commercial aircraft and 7 wide - board commercial aircraft are presented. it is found that the landing gear noise spectrum is broadband with some single tones in some cases. the directivity of the total sound pressure level of a landing gear noise resembles that of a horizontal dipole. the level differences between the various aircraft landing gears are larger than those expected from the airspeed differences. it is thus expected that the louder noise emission of the landing gears can be reduced by redesigning
文摘:應用由111個傳聲器組成的平面傳聲器陣列對當前流行的民用客機進場著陸過程中的機體噪聲源進行了實驗測量，本文對七架窄體客機和七架寬體客機的起落架噪聲進行了分析，得到了起落架噪聲的頻譜特性、指向特性和聲級變化.研究發現，起落架噪聲的頻譜是由寬頻隨機噪聲與一些較為明顯的單音噪聲源組成，起落架噪聲的指向性類似於一個水平放置的偶極子.不同飛機起落架噪聲的聲級相差較大，這說明可以通過重新結構設計降低起落架噪聲。 -
Based on the previous theory, the fdtd method is used to analyze practical antennas, which include dipole antenna, microstrip antenna, log - periodic antenna and broadband resistance loaded monopoles. the particular problems that occur in the calculating of vary type antennas are discussed. the cross - section field of microstrip line and two - conductor line are analyzed, and the effect on the numerical result arising from the incident cross - section mesh size is discussed
在前面理論的基礎上，將fdtd用於振子天線、微帶天線、對數周期天線、電阻加載振子天線等各種天線的計算中，對各種不同類型天線計算中所遇到的特殊問題進行了詳細的討論，並分析各種開放場傳輸線如微帶線、平行雙線等橫向場分佈，討論了入射網格橫向截斷區域的大小對計算結果的影響。
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