旁帶頻率 的英文怎麼說
中文拼音 [bàngdàibīnlǜ]
旁帶頻率
英文
side band frequency-
A patch antenna with etched holes on the ground plane is also studied. the performance of the antenna at the resonant frequency is analyzed by using the fdtd method together with the pml boundary treatment. the results show that the surface waves are suppressed greatly, the bandwidth is improved and a 1 odb reduction on the sidelobe level is achieved at the 110 and 260 directions in the e plane
全面地研究了地面腐蝕周期圓孔結構的電磁晶體貼片天線在基波頻率處的性能，用fdtd方法並結合pml邊界處理技術對該天線所取得的研究結果顯示，本文設計的地面腐蝕型電磁晶體結構抑制了貼片天線中的表面波，增加了天線的帶寬，並有效地削弱了旁瓣，使天線的e面方向圖上110和260方向的兩個旁瓣被削弱了10db 。By theory and practice simulation, the several types of constant envelope modulation techniques are analyzed and compared, including theirs modulation principle, phase path, the modulated wave envelope, power spectrums, error bit rate and the influence of its power spectrums of the band - limited and non - linear, etc. especially we have researched the ijf - oqpsk modulation technique, and the performance of its inter - symbol interference and time jitter free, and its strongly resisting of spectral spreading
結合理論和實驗模擬結果，分析討論了衛星通信中的各種恆包絡調制技術，對它們的調制原理，相位路徑，已調波包絡，功率譜密度，誤碼性能，以及帶限非線性通道對其功率譜的影響等方面都作了研究和比較。特別研究了ijf ? oqpsk在消除碼間干擾和定時抖動方面的性能及其優良的旁瓣特性和抑制頻譜擴展特性。Frequency code is not uniformity distribution and keeps to a probability distribution function defined by the spectral characteristics of the target of interest. the phase code is equally duality pseudo - random sequence and used to reduced the sidelobes of the signal correlation function. and the mismatch - phase sequence is corresponding with the frequency sequence one by one
而頻率編碼為不均勻分佈，由所觀測目標的頻譜信息提取出概率密度函數決定頻率編碼序列的分佈；相位編碼為二元的偽隨機序列，採取均勻的二相編碼，消減同頻脈沖帶來的過高的相關函數的旁瓣；而失配相位為與頻率編碼相一一對應于各子脈沖中。Thirdly, a modified extended chirp scaling ( ecs ) algorithm is presented, which solves the problem of producding fine focused images in the class of chirp scaling ( cs ) algorithm. lt can be used for uwb - sar imaging effectively. the phas e error produced by cs operation are analyzed. a windowed process in two dimension frequency domain before cs operation are proposed. it can improve the quality of image and widen the effectively swath and increase the peak to sidelobe ratio ( pslr )
然後針對chirpscaling （ cs ）類演算法不能對參考點精確聚焦的問題，提出了一種改進的擴展cs （ ecs ）演算法，實現了對uwb - sar的高效成像；分析了cs操作產生的相位誤差，提出在cs操作之前在二維頻率域對信號加窗，除有效提高信號的峰值旁瓣比（ pslr ）外，還可以提高圖像質量，增加有效測繪帶寬度。分享友人