frequency modulated wave 中文意思是什麼
frequency modulated wave
解釋
調頻波-
Based on the method, this dissertation deals with several kinds of signals including cosine wave ( cw ), linear frequency modulated ( lfm ) and multi - component signal, furthermore the systematic comparison of estimation effect among cwt and several other usual methods as well cramer - rao bound ( crb ) is given
基於上述方法，文中分別對單頻矩形脈沖信號、線性調頻脈沖信號以及多分量信號進行了瞬時頻率估計，並與其他幾種常用瞬時頻率估計方法的性能以及crb進行了系統比較。 -
The carrier wave is modulated directly by the baseband signal at several frequency point in l band and s band. firstly, this paper clarifies the theory of i / q modulation, elaborates evm and acpl, and analyzes the effect of amplitude and phase unbalance and dc offset on evm. secondly we review the basic principle of phase locked loop and it ’ s composing parts, including the basic conception and design method of pll frequency synthesizer, especially introduce the charge pump pll frequency synthesizer in detail
首先，在闡述i / q正交調制基本原理的基礎上，通過對誤差矢量和鄰近通道功率泄漏的詳細分析，定性、定量地討論了各種非理想電路因素（如相位不平衡、幅度不平衡、直流偏差等）對調制器性能的影響;其次，介紹了鎖相環的工作原理和基本組成部分，包括鎖相環的設計和環路濾波器的設計，特別詳述了電荷泵鎖相頻率源;第三，介紹了採用直接調制技術模擬衛星信號的射頻前端的設計;最後，對整個直接射頻調制系統進行測試，結果基本上達到了課題要求。 -
The new technology of non - contact life - parameter detection is relative to that of the normal contact one, which uses microwave beams to illuminate the human subject, whose reflected wave will be modulated by the surface movement resulting from the physical activity. by this way, some parameters of the reflected wave, such as frequency and phase will be changed. if these changes can be detected, the life parameters such as respiration rate and heartbeat rate will be extracted from those changes
非接觸生命參數檢測是相對于常規的接觸式檢測而言的一種新技術，它利用微波束照射人體，其回波信號被人體生命活動引起的體表微動所調制，使得回波信號的某些參數（如頻率、相位）發生改變，檢測到這些變化就能從中提取出人體的生命參數（如呼吸或心跳） 。 -
According to the target distance ( 5 ~ 50m ), a c - band transceiver for ranging was presented in this thesis. the focus of this work was on designing a c - band frequency - modulated continuous - wave ( fmcw ) frequency source, a receiver and microstrip antenna
本文針對所探測目標的距離（ 5 ~ 50m ） ，研製了c波段測距收發前端，主要包括c波段調頻連續波（ fmcw ）頻率源，接收電路以及微帶天線。 -
Traditional laser iff has poor security because of low frequency of laser beam coded pulse. this can be greatly improved when the pulses are modulated by continuous wave laser, but the power of this laser beam output is so low that it ’ s difficult to be detected and received by laser warning subsystem
傳統的激光敵我識別器激光編碼脈沖頻率低，通信保密性差，使用連續波激光器經調制后激光編碼脈沖頻率高，保密性好，但輸出激光功率較低，難以達到激光告警分機探測接收的要求。 -
There are five parts are as follows : in part one, the concept of switching function is introduced first to establish the nonlinear mathematical model of the induction motor variable frequency speed adjustment system which is fed by a sine pulse width modulated ( spwm ) inverter and takes the effect of the main magnetic circuit saturation into consideration, then the low frequency oscillation of the system is simulated according to the model. next, from the view point of energy conversion of the inverter - induction system, a criterion for the low frequency oscillation is proposed to determine whether the system is in low frequency oscillation which is judged by whether the interval of the negative current component of the inverter input current is more than 1 / fc ( fc is the carrier wave frequency of the inverter ) or not
首先引入開關函數概念，建立了正弦脈寬調制（ spwm ）逆變器供電異步電動機，考慮主磁路飽和時的變頻調速系統整體數學模型，模擬系統的低頻振蕩；其次從逆變器-異步電動機系統能量轉換角度出發，提出通過檢測逆變器輸入電流中負電流的間隔時間是否大於1 / f _ c （ f _ c為逆變器載波頻率）來判定系統是否出現低頻振蕩；最後的實驗結果驗證了系統低頻振蕩建模和判據的實用性和正確性。 -
Briefly, here are main topics of this dissertation : ( 1 ) the relation between the resolving power of the linear frequency modulated continuous wave radar and the linearity of linear frequency modulation signal
同樣，輸出數據也可以通過雙口ram和pci介面輸出。本文的主要工作包括： （ 1 ）介紹了線性調頻雷達距離分辨力和調頻線性度的關系。 -
The basic principle, main properties, typical parameters, technical characteristics and general situation of klystron are introduced. the electron beam prebunching in the modulated cavity and shift tube of relativistic klystron amplifer ( rka ) is studied analytically, a self - consistent equation of radiation generated by the prebunched electron beam in the radiation cavity is derived using the field method of particle ? wave interaction instead of the electrical circuit method, and in terms of it, the gain in the linear regime calculated, a field analysis method is proposed. the theory analysis shows that the characteristic parameters, such as resonance frequency, real part of gap - impedance, external quality fadtor in all kinds of klystron output circuits including single - beam, multi - beam, single - gap, multi - gap, single - beammulti - gap, multi - beam multi - gap klystron output circuit, can be calculated by the field analysis method
本文系統的介紹了速調管的工作原理、主要特點、發展概況、主要性能指標和技術特點，解析的研究了電子束在相對論速調管放大器的調制腔和漂移管中的預群聚;用粒子波互作用的場方法導出了在輻射腔中預群聚電子束產生輻射的自洽方程，同時對線性區的增益進行了計算。理論分析表明，場分析法可用於計算單注單間隙、多注多間隙、單注多間隙和多注多間隙速調管輸出迴路的諧振頻率、間隙阻抗實部和外觀品質因數等特性參數。 -
The main limitation of a intensity - modulated - continuous - wave laser rangefinder is the leakage distortion created by the high frequency current source which modulates the laser diode
在調強連續波激光測距系統中，調制激光器的高頻電流源產生的泄漏干擾是影響測距精度的主要因素。 -
In this dissertation, at first, introducing the theory of linear frequency modulated continuous wave radar. the designing of the signal processing hardware platform is basing on the algorithm
在本文中，首先介紹了線性調頻雷達的工作原理和相關的理論，根據這些演算法要求，來設計信號處理的硬體平臺。 -
Linear frequency modulated continuous wave ( lfmcw ) radar has many characteristics of simple structure, small volume, light weight, low cost, low transmitter peak power, short wavelength, thus it is especially suitable to be used in radar image, research of target characteristic, end control and guide, battlefield spy, scene watch etc. and more people in the world interested in it, it will have a wide prospect
線性調頻雷達具有結構簡單、體積小、重量輕、造價低、發射峰值功率低、波長短等一系列優點，特別適合於雷達成像、目標特性研究、末制導、戰場偵察和場面監視等領域，目前已受到國內外的廣泛重視與研究，應用前景十分誘人。 -
Variable frequency speed regulation system based on the voltage space - vector is researched in this paper, the principle of the voltage space - vector is presented, and the third part " s software strategy of voltage space - vector is analyzed, the method of the third part " s software of voltage space - vector is imitated with simulink. at the same time, the duty time and duty order of the two zero - vector are analyzed and showed that the voltage space - vector pwm is actually a modulated method by adding the harmonic to the sine wave
本文對基於空間電壓矢量的變頻調速系統進行了研究，敘述了空間電壓矢量的原理，對ti公司第三方軟體的對稱空間電壓矢量的演算法進行了分析，並用simulink對該方法進行了模擬，對兩個零矢量的作用時間和作用順序進行了分析，指出空間電壓矢量pwm實質上是一種諧波注入的調制方法。 -
Frequency modulated continuous wave synthetic aperture radar ( fm - cw sar ) can be miniaturized, and it is fit for light - duty flight platform wonderfully
調頻連續波合成孔徑雷達可以實現小型化，能非常好地滿足輕型飛行平臺對成像設備的要求。 -
With the development of the self - oscillating mixer ( som ) theory, the application of som has been studied thoroughly and shows potentials in many fields. this paper introduces the development of som technology in the pass few years at first. then it shows some popular nonlinear techniques used in analyzing the nonlinear circuits. the technology of som can be used in the doppler radar for velocity measurement and in frequency modulated continuous wave ( fmcw ) for distance measurement
本文通過對自振混頻技術基本理論的研究，介紹了對非線性電路進行分析的理論方法以及在自振混頻器技術分析中的應用，然後對自振混頻技術在多普勒測速雷達和調頻連續波（ fmcw ）雷達上的應用進行了研究。 -
The author designed and developed a single phase mid - frequency inverter control unit, which is based on dual micro - processor system. the inverter is modulated by pre - set spwm pulse width wave
本文研製出一種基於雙微處理器（ mpu ）控制的單相中頻逆變電源控制裝置，逆變電路基於開關預置spwm波脈寬調制。 -
It demonstrates the general project of vehicles mutual moving - state detection and control system, which use a frequency modulated continuous wave ( fmcw ) radar with the antenna replaced by a frequency scanning array as the basis of detecting sensor
文中闡述了汽車相互運動狀態監控系統的總體方案，使用調頻連續波（ fmcw ）雷達作為探測傳感器的基礎，並在天線部分作了改進，採用了獨立的頻率掃描天線。 -
The unsteady input commercial frequency sinusoidal voltage with high harmonic is modulated into bi - polarity three - state high frequency ac volage by the input cycloconverter, bi - polarity three - state high frequency ac volage is demodulated into uni - polarity three - state spwm wave by the output cycloconverter, and the uni - polarity three - state spwm wave is filter into steady commercial frequency sinusoidal voltage with low harmonic
輸入周波變換器將輸入不穩定劣質的工頻正弦交流電壓調製成雙極性三態的高頻交流電壓波，輸出周波變換器將此高頻交流電壓波解調成單極性三態spwm波，經輸出濾波后得到穩定優質的工頻正弦交流電壓。 -
The pseudorandom codes have a good autocorrelation of double - values. in recent years, to solve the problems of anti - interference and the ambiguity of range and velocity, a lot of countries do much research to change the waveform of radar signal. the most important improve is to use symmetrical pulses to interrupt frequency modulated continuous wave ( fmpcw )
早期的fmicw採用偽碼序列截斷，偽隨機碼具有良好的雙值自相關特性，其中最常用的是m序列截斷的fmicw 。近年來，為了解決抗干擾和測距、測速模糊問題，許多國家已對雷達信號波形的改進進行了研究。 -
Then to meet the problem of the separate between receiving and transmitting for single - station radar system in continuous wave principle, we introduced frequency modulated interrupted continuous wave ( fmicw ). in early days, the pseudorandom codes were often used in fmicw. usually m - sequence is used to intertupt frequency modulated continuous wave
之後，為了解決連續波體制下，單站收發共址的雷達系統的收發隔離問題，又普遍採用了截斷的線性調頻連續波信號形式，叫做線性調頻中斷連續波信號（ fmicw ） 。 -
This paper presents an integrated comparison of object - detecting techniques, the techniques that base on millimetre wave frequency modulated pulse - doppler radar is chosen on the basis of the idiographic demand of the recws
通過對車載目標探測技術的綜合比較，結合本報警系統的具體要求，選用了車載毫米波調頻多普勒雷達目標探測技術。
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