small frequencies meaning in English
小频数
Examples
- The components occur at infinitisimally small frequency .
分量是在无限小频率间隔上出现的。 - The task of carrier synchronization is tracking the frequency and phase of a carrier wave , the most effective means for tracking small frequency deviation and the phase of a carrier is using the phase - locked loop ( pll )
载波同步的任务就是跟踪载波的频率和相位,对于载波相位及小频偏的跟踪,最有效的方式是使用锁相环。 - Through the research of direct digital synthesizer ( dds ) used as a divider in phase lock loop ( pll ) , a frequency synthesizer with small frequency resolution ratio and high purity frequency spectrum can be realized
摘要通过对直接数字合成器在锁相环路中作为分频器应用的研究，使频率合成器可以在实现超细频率分辨率的同时达到高的频谱纯度。 - By making full use of favourable narrow - band tracing filter character of pll and by combining the merits of dds such as super fine frequency resolution 、 high frequency accuracy 、 very fast frequency hoping with it , the pll / pll + dds frequency synthesizer presents wide band high quality source and super small frequency hoping step . while the electronically tuned filter abates the image interference and notably improves the selectivity . the theorem of frequency synthesizer and center - frequency - fixed filter is simply but adequately introduced first in this paper
课题中所采用的pll或dds pll锁相频率合成方法充分发挥锁相环良好的窄带跟踪滤波特性，并结合dds的高频率分辨率、高频率精确度和高速频率捷变等优点，分别实现了系统所要求的高质量宽带本振源和小步长频率捷变；采用电调谐选频技术，则大大改善了接收机的选择性和抗干扰能力。 - In this system two oscillator are used for mixing . pll for high local oscillator and dds + pll for low local oscillator . by making full use of favourable narrow - band tracing filter character of pll and by combining the merits of dds such as super fine frequency resolution , high frequency accuracy , very fast frequency hoping with it , the pll / pll + dds frequency synthesizer presents wide band high quality source and super small frequency hoping step
系统采用两次混频，其中高本振的设计采用pll锁相环频率合成来实现，充分发挥了锁相环频率合成器的优良特性，实现了系统所要求的高质量宽频带本振源；低本振采用pll + dds频率合成来实现，结合pll优良的锁相特性与dds的高频率分辨率、高频率精确度等优点，实现了频率的小步进高精度合成。