查询词典 frequency modulation

After this text introduced and will imitate the audio frequency signal processing as numerical signal after red shoot outside, the numerical signal that will receive again solution adjust after the audio frequency power enlarger enlarge restore in order to imitate the speech signal, shot the electric circuit outside analyzed to design the audio frequency signal before collecting the electric circuit, signal placed the big electric circuit, frequency to make the electric circuit, red, red circumscribed to accept the electric circuit,, frequency the solution adjusted the electric circuit and audio frequencies to enlarge the electric circuit etc.

本文介绍了将模拟音频信号处理为数字信号后经红外发射，再将接收到的数字信号解调后经音频功率放大器放大后还原为模拟语音信号，在分析设计了音频信号采集电路、信号前置放大电路、频率调制电路、红外发射电路、红外接收电路、、频率解调电路以及音频放大电路等各组成部分。

Radio Frequency Identification System BE make use of RF energy to deliver data,belong to a wireless communication technique,is 1 kind not the system of contact type,it constitutes the component contain the application system of the reader,electron label,Antenna,host computer, its induction method depends on passive type Tag with active type Tag distinguish analyse, can be divided into induction coupling and back scattering coupling and induced the coupling is the induction method (as 135 KHzs、13.56 MHzs) which belongs to low frequency、high frequency,the back scattering coupling is the induction method(as 915 MHzs、2.45 GHzs) which belongs to superhigh frequency,microwave, and what we construct apply system is use the high frequency 13.56 MHzs of induction coupling method.

中文摘要无线射频辨识系统(Radio Frequency Identification；RFID)是利用RF能量来传递资料，属於无线通讯技术，是一种非接触式的系统，其组成元件有读卡机、电子标签、天线、主电脑应用系统，其感应方式依被动式Tag和主动式Tag来区分，可分为感应耦合和反向散射耦合而感应耦合是属於低频、高频的感应方式(如135KHz、13.56MHz)，反向散射耦合是属於超高频、微波的感应方式(如915MHz、2.45GHz)，而我们所建构的应用系统是使用高频13.56MHz的感应耦合方式。

The transmit part adopts the phase-locked loop pattern of frequency synthesizing technology and uses the MC145152 and MC12022 chips to compose the phase-locked loop.It locks the frequency of the carrier-wave at 35MHz.The stabilization of the carrier-wave can be 4×10-5,the accuracy can be 3×10-5.The frequency modulation and the confection of the carrier-wave are realized by the capacity-changing diode V149 and the integration voltage-control oscillator MC1648 chip.The end power amplifier uses the audion 2SC1970 to make it work in the third magnifying state,it improves the efficiency of the magnifier and the power of the output reaches the design demand.

发射部分采用锁相环式频率合成器技术， MC145152和MC12022芯片组成锁相环，将载波频率精确锁定在35MHz，输出载波的稳定度达到4×10-5，准确度达到3×10-5，由变容二极管V149和集成压控振荡器芯片MC1648实现对载波的调频调制；末级功放选用三极管2SC1970，使其工作在丙类放大状态，提高了放大器的效率，输出功率达到设计要求。

The high efficiency transistor development causes the frequency changer the construction cost more and more to be also low, from the cost and the performance considered selects PLC to the frequency changer control realization frequency conversion velocity modulation.

大功率晶体管的开发使变频器的造价也越来越低，从成本和性能考虑选用PLC对变频器控制实现变频调速。

In the past, the high frequency resonance technique is usually applied in the envelope detection for a vibration signal with amplitude modulation. When applying the Hilbert transform in the high frequency resonance technique for the envelope detection of vibration signals, the computing burden is very high. On the other hand, when applying the linear least squares analysis method, the computing burden is lower. When applying the envelope detection in the lowest vibration mode, an accelerometer with the low-pass filtering cutoff frequency at 4kHz should be choose.

在过去的研究方法中，振动讯号之振幅调变通常以高频解调分析法应用於包络讯号侦测，而高频解调方法应用希尔伯特转换的包络分析，所需要的计算量是非常的高，若以线性最小平方分析法应用於高频解调分析法中，则所需要的计算量较小，如果以最低模态来估测包络讯号时，可以适当的选取加速规来代替低通滤波器，而加速规的截止频带必须在4kHz左右。

In this study, two-tone stimulus paradigm with inter-pulse interval of 50 ms was used and two kinds of maskers, static frequency masker and dynamic frequency masker (up-sweep frequency modulation sound), were delivered to the animal before the probe under free field stimulation conditions.

自由声场刺激条件下，采用一定间隔的双声刺激模式(前一个声音为掩蔽声，后一个声音为探测声)，记录昆明小鼠下丘(inferior colliculus， IC)神经元的声反应。

The calls of non-passerine are some kinds of monotonous dull vocalizations with the characteristics of low and deep frequency, single syllable, low basic frequency and with no ability of modulation in frequency and amplitude. Most of the calls are monotonous and low quality mainly based on the basic song. Compare the vocal of sub-oscine passerine with non-passerine, they have some similar aspects, but the former possesses of stronger capability of vocal control.

非鸣禽的叫声低沉而单调，音节种类单一，基本音频率低，缺乏频率调制以及幅度调制的能力，叫声的品质因数很低，不悦耳，大多为以基本音为主的单音调低音品叫声，亚鸣禽的叫声与非鸣禽近似，但在控声能力方面又有所提高。

On the basis of analyzing the oscillatory frequency of crystal oscillator , the general expression of the frequency deviation of crystal frequency modulation oscillator is de rived .

本文在分析晶体调频振荡器振荡频率的基础上，得出了晶体调频振荡器频偏的一般表示式，最佳负载条件下的频偏设计公式和调制级有电流串联负反馈时的频偏设计关系式。

This paper mainly analyses dispersion frequency signals time and frequency property of triangle wave modulation. Real 5mm dispersion frequency signal is collected. The theory data and real data are compared and analyzed. It shows 5mm radar forepart is practicable, it also supplies theory base to design back signal processing circuit.

主要完成了三角波调频体制下的差频信号在时域和频域两方面的特性分析，并采集了5mm波段实际的三角波调制差频波形，通过将理论值与实测值的比较分析，表明5mm样机前端部分的可靠性，为后面的信号处理电路设计作准备。

Using upper sideband also allow the actual carrier frequency to be determined easily simply by adding the dial frequency to the audio modulation frequency.

使用上边带还允许实际载波频率确定仅仅通过增加拨号频率的音频调制频率容易。

Through comparing with the results by simulation to study the effects of theprojectile"s final velocity, the angle of rotation and the ballistic trajectory"s migration withdifferent projectile"s rotating speeds, different target"s moving speeds and differentpenetration angles.

通过比较数值模拟的结果来研究不同弹头转速、目标速度、侵彻角对侵彻过程中弹头最终速度、翻转角度和弹道偏移的影响。

I love stationery and all the accoutrement of writing.

我爱文具以及所有的书写的工具装备。