标称频率 meaning in Chinese

nominal frequency
nominalfrequency

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
本研究采用一阶温度系数为零的压电石英基片上制作出损耗小于5db 、有载品值因素( ql值)超过1000的一系列低损耗、高q值声表面波rayleigh波或stw谐振器,频率分别为60mhz 、 280mhz 、 739mhz和1ghz等不同频率的高性能声表面波谐振器。并采用噪声系数为1 . 25db的低噪声系数放大器,精心设计电路,优化设计布置印制电路板,用标称频率为1ghz的声表面波谐振器为频率控制元件,制作出在偏离载频1khz处的单边带相位噪声近- 120dbc / hz 、杂波抑制达80db以上的低相位噪声声表面波振荡器。