In the paper , the design of the real - time test system for crystal parameters is presented . the signal generator of sweep frequency based on dds device ad9852 , the signal measuring circuit based on gain and phase detector ad8302 , and the real - time control and deal circuit based on tms320vc5416 and the design of high - speed printed digital & analog circuit board are discussed in details 本文阐述了晶振实时测量系统的设计，介绍了以dds芯片ad9852为核心的扫频信号源电路，以增益相位检测器ad8302为核心的信号检测电路，以dsp芯片tms320vc5416为核心的实时控制与运算电路，以及高速数模混合电路板的设计方法。
The road sweeping cleaning , enhancing sweeping frequency , asking for " seven - eight net , " that is no deposit , no litter ( pack ) , the peel of debris - brick , sand , mud without water , without tanji stains , ground - graffiti was chaos posted , the road net , net wellhead groove , lower part of wall net , net - poles , tree point net , net roadside stone teeth , green belts , net , net garbage bin 在道路清扫保洁方面，提高清扫频率，要求达到“七无八净” ，即无堆积物、无垃圾（包） 、无果皮纸屑、无砖瓦土石、无污泥积水、无痰迹污渍、地面无乱涂写乱张贴，路面净、沟井口净、墙根净、电杆根净、树穴净、路边石牙净、绿化带净、果皮箱净。
First , the ray tracing equation and its numeric solution is presented in this paper , then on the base of quasi - parabolic ionosphere model , using the technology of the numeric ray tracing , a ray tracing simulateing platform is established . this platform can simulate the ray tracing for a fixed frequency or sweeping frequencies , also can calculate the group path and the covered region of rays 首先,本文给出了射线追踪方程及其数值解法,在球形对称准抛物模型背景电离层基础上,利用数字射线追踪方法,建立了射线轨迹演示平台。该平台可实现定频或扫频射线轨迹演示,计算各射线群路径,覆盖区域等功能。
