acoustic zero 中文意思是什麼
acoustic zero
解釋
聲學零分貝-
" l ' lle brief introduction of underwater acoustic channel and the cl1art of image transmission syste111, innovation of ti1is paper are given in the first chapter. basic technology and hardware using in this project are introduced in the seco11d chaptel transform methods, especially the wavelet transformation are introdtlced il1 the tl1ird cllapter. ii11age ' s coding methods are introduced in cl1apter four, witll tilem ti1e zero tree method is the el11pl1ases
第一章給出對水聲通道特性簡介以及圖像信息傳輸的系統框圖、本研究創新之處；第二章介紹圖像處理的基本技術以及本研究的硬體環境；第三章介紹圖像數據的變換方法，著重介紹了小波變換涉及到的知識；第四章介紹圖像編碼，重點介紹了零樹法編解碼；第五章介紹本研究的軟體、硬體設計、對零樹法的具體改變。 -
At present the manufacture of surface acoustic wave use the technology of the final submicron. a series of the devices of low insertion loss, high q saw rayleigh surface acoustic wave resonators or stws that insertion loss has less than 5db, load quality factor ( ql ) is more than 1000 on the quartz piezoelectric with zero of first temperature factor in the research. these difference frequencies are 60mhz, 280mhz, 739mhz and 1ghz of normal frequency and at also surface acoustic wave. using 1. 25db noise factor amplifier, careful design curcuit, good setting printed curcuit board, and using the 1ghz surface transverse wave resonator as frequency element, researching the low phase noise surface acoustic wave with sideband phase noise near ? 120dbc / hz deviating 1khz on carrier, spurious suppress with 80db
本研究採用一階溫度系數為零的壓電石英基片上製作出損耗小於5db 、有載品值因素（ ql值）超過1000的一系列低損耗、高q值聲表面波rayleigh波或stw諧振器，頻率分別為60mhz 、 280mhz 、 739mhz和1ghz等不同頻率的高性能聲表面波諧振器。並採用噪聲系數為1 . 25db的低噪聲系數放大器，精心設計電路，優化設計布置印製電路板，用標稱頻率為1ghz的聲表面波諧振器為頻率控制元件，製作出在偏離載頻1khz處的單邊帶相位噪聲近- 120dbc / hz 、雜波抑制達80db以上的低相位噪聲聲表面波振蕩器。
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