頻帶展寬比 的英文怎麼說
中文拼音 [bīndàizhǎnkuānbǐ]
頻帶展寬比
英文
bandwidth expansion ratio-
For bowtie antennas, this method can produce a better return loss in the higher frequency band than the original ones, and at the same time, the radiation pattern bandwidths of the new antennas can be broadened more or less
對蝴蝶結天線而言，應用這種方法得到的蝴蝶結天線在高頻段比原天線具有更好的反射損耗，天線的方向圖帶寬有不同程度的擴展。In order to supply the main two services ? vod ( video on demand ) and iptv which are used popularly in the application, 8010r & d designed a new streaming media system based on our new operating system named digital organic system ( dos ) with high dependability, high concurrence, low - price - high - efficiency and high retractility as its characters. in our stream media system, there are three important components
當前政府正在大力推廣internet及寬帶網路，加之正在興起的網路電視計劃，這些因素極大的推動了網路流媒體業務的迅速發展。針對目前流媒體應用最廣泛的視頻點播和在線直播服務， 8010實驗室自主研發了具有高可靠性、高並發性、高性價比及高伸縮性的數字有機體流媒體播放系統。The time base drift deduced by the change of temperature is discussed particularly and the compensation method of it is analyzed. finally, we also studied frequency band extension under time base distortion condition by simulation. the results show that the compensation of time base distortion can reduce the error of signal and then increase the accuracy of frequency band extension
首先，介紹時基失真的相關概念及其對測量信號的影響；其次，對時基失真特性測量的不同方法進行了理論分析和比較，並對分析信號法進行了模擬研究；再次，對時基失真的補償方法進行分析和模擬研究；並專門對溫度變化引起的時基漂移及其補償方法進行了簡要分析；最後，對時基失真條件下的頻帶展寬技術的模擬表明時基失真的補償可以減小信號的誤差，因而提高頻帶展寬的精度。None but is the test spectrum abundant and controllable, it is possible to simulate the stresses environment needed for exposing weakness of the product. based on summarizing the present status of the vibration test and vibration environment simulation technology in the world, the topic of simulation of super - gaussian random vibration environment with controllable frequency spectrum and its applications in reliability enhancement testing is put forward. the main content and conclusions of the dissertation are as following : 1
本文在綜述國內外振動試驗技術和振動環境模擬技術的基礎上，引出「頻譜可控的超高斯隨機振動環境模擬技術及其在可靠性強化試驗中的應用」這一主題，並緊緊圍繞該主題開展了如下研究工作: 1 .全面分析了振動激勵的功率譜密度量級、幅值分佈、帶寬以及試件結構的固有頻率、阻尼比等因素對疲勞損傷累積的強化效應，提出振動強化試驗激勵信號應具備的重要特性:頻譜可控和超高斯，確立了本文的研究主題和方向。For the operating frequencies of modern radars and guidance 、 electronic countermeasure system 、 communication system 、 remote sense and remote measurement system expand to millimeter band step by step, the operating frequencies of t / r module raise ceaselessly. simultaneity millimeter wave t / r module which has the advantages of small dimension, lightweight, wide band is more suitable to the requirement of modern army and communication system. this paper is mainly referred to the research of t / r module in ka band
現代雷達與制導、電子對抗、通信、遙感遙測系統的工作頻率已逐步由微波波段擴展到毫米波波段，因此t / r組件的工作頻率也在不斷的上升，同時，毫米波t / r組件與微波t / r組件相比具有尺寸小、重量輕、頻帶寬等優點，更適合現代軍事和通信系統的要求。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。However, to achieve this objective, various technical challenges must be overcome. for example, the deployment of broad - band wireless access systems would require a transmission technique which can mitigate the detrimental effects of frequency selective fading
為達到這一目的，有一些技術問題必須得到良好的解決，比方說在寬帶通信模式下由於延遲擴展造成的頻率選擇性擴展和由多普勒效應產生的通道時域衰落。分享友人