modulated frequency 中文意思是什麼
modulated frequency
解釋
調制頻率-
By analysis, two kinds of caq are found : one is width - modulated countable pulse series, the other is frequency - modulated countable pulse series. furthermore, the method of generating caq is described and its double features is also proved
通過分析找到兩種計數型模擬量：調寬計數脈沖串和調頻計數脈沖串，同時本文也闡述了計數型模擬量的產生方法，並進一步驗證了它的二象性特徵。 -
The second, at the high frequency primary coil, when switch turn on with control signal ( the spwm pulse is modulated ), in the positive or negative semi - period of low frequency modulation signal, transformer coil with same direction voltage. the magnetic flux of transformer core will increase step by step. at the end, it leads to magnetic flux saturation
二、在高頻變壓器原邊，當開關管接收控制信號脈沖列（經調制的spwm波列）導通時，在低頻調制信號的正半周或負半周內，施加在變壓器繞組上的是同一方向的電壓，變壓器磁芯中的磁通可能將級進地逐漸增加，導致磁芯飽和，造成磁偏或單向磁化，導致低頻電信號放大失真或由於很大的磁化電流而無法正常工作。 -
In the fourth chapter, firstly, the fsk / psk signal function is presented, then, the signal which frequency and phase are modulated by costas code and barker code for each are analyzed at the same time. after that, the target returns and clutter returns are analyzed and modeled. at last, both of the time correlation characteristics and space correlation characteristics are theoretically analyzed
在第四章中，首先給出fsk / psk信號的表達式，並對一種分別採用costas碼和barker碼進行頻率和相位調制的fsk / psk信號進行分析，然後對fsk / psk信號的目標回波和雜亂回波進行分析與建模，接著，對雜波信號的時間相關性和空間相關性進行理論分析，由分析結果可知， fsk / psk雷達雜波的時間相關性不變、空間相關性增強。 -
The corrosion current and impressed against - corrosion current of a ship modulated by shaft ' s rotation will generate an extremely low frequency electric field ( elfe ) which becomes a kind of important characteristic signal in sea water
摘要艦船的腐蝕和防腐電流經螺旋槳轉動的調制后在海水中會?生極低頻電場，成?一種重要的特徵信號源。 -
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 united signal for the isar signal processing is called the cross - range dimension signal. the cross - range dimension signal of the target with nearly tangent motion is a linear frequency modulated signal
由推導的準切向運動目標的方位向信號的相位表示式可以看出，此信號近似為線性調頻信號。 -
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。 -
This waveform library not only contains those typical radar signals like single - carrier frequency signal, encoded signal, lfm etc, but also include many hybrid modulated signals, like fsk / psk signal, fsk / ppm signal, psk / ppm signal, pseudo - random fsk / psk signal, etc. we use visual c + + 6. 0 to implement this software program, this makes it easy in control operation and provides a nice human - machine interactive interface
波形庫中既包含了傳統的雷達波形，如單載頻脈沖信號、 lfm 、編碼信號等，又包括了復合調制波形，如fsk / psk信號、 fsk / ppm信號、 psk / ppm信號、偽隨機fsk / psk信號等。採用vc編程實現，使其具有友好的人機界面和靈活的控制操作。 -
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） 。 -
Since the envelope of modulated signal fluctuates, these methods generate unwanted intermodulation distortion ( imd ) products in a nonlinear radio frequency ( rf ) power amplifier ( pa ). so it is necessary to use linearization technique to reduce the adjacent channel interference ( aci )
但包絡變化的調制信號經過非線性射頻功放后會產生交調分量，因此必須採用線性化技術來減少由此產生的鄰道干擾。 -
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。 -
The thesis firstly analyzes the signal form of frequency modulated interrupted continuous waveform ( fmicw ) in theory, studies the principles of detecting range and velocity for fmcw, and further discusses the essential processing methods of the fmicw signal form, including the range transform processing method based on the strict corresponding relation between time and frequency domain, the velocity doppler transform, the digital beam forming
本文首先從理論上分析了在高頻地波超視距雷達所用的線性調頻斷續波信號的形式，研究了fmcw雷達測距測速原理，並深入地探討了fmicw信號的基本處理方法以及具體的演算法，主要包括距離變換中採用的時間波門相關處理方法，速度多普勒變換，數字波束形成。 -
The feedback of the output voltage is the major control loop. to achieve better frequency response and disturbance rejection of the input voltage, a input voltage feed - forward system is introduced in control loop. the duty - cycle of pwm applied at the gate of power mosfet is modulated by both input and output voltage
該晶元採用的控制方式為電壓型pwm （脈沖寬度調制， pulsewidthmodulation ）控制方式，以輸出電壓反饋作為主要控制參量，同時為了提高晶元對輸入電壓擾動的響應速度，採用了輸入電壓前饋方法，將輸入電壓因素引入了反饋控制環中，通過對輸入輸出電壓的檢測，控制加在功率mos管柵極電壓上矩形脈沖的占空比，進而調節輸出電壓。 -
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。 -
Linear frequency modulated ( lfm ) signals as the most popular pulse compression signal are a typical kind of time - varying, nonstationary signals, so applying the wigner - ville distribution into lfm signals has more advantages than conventional methods
雷達脈沖壓縮技術中所使用的線性調頻信號是一類典型的時變非平穩信號，採用時頻分析的研究方法處理線性調頻信號有著傳統方法無法比擬的優點。 -
Equipment and components used in cabled distribution systems primarily intended for television and sound signals general specification for frequency modulated stereo and monotonic modulators
電視和聲音信號的電纜分配系統設備與部件調頻立體聲和單聲道調制器通用規范 -
Methods of measuring and expressing the performance of radio receivers for sound broadcasting - measurement on frequency - modulated receivers of the response to impulsive interference
無線電廣播接收機性能測定及表示方法.第5部分:調頻接收機脈沖干擾響應測量 -
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。 -
Comparing with the traditional phase - shifted laser range finder, the method could implement the ranging with multifrequency by using single modulated frequency. it could not only solve the contradiction of the range and the precision, but has high degree of accuracy and wide range, simplify the hardware design, and reduce the cost. this paper introduced the theory of phase distance measurement, analyzed various testing methods and expatiated the hardware and the software for the proposal system
與傳統的相位法測距相比，本方法使用單調制頻率實現了多頻測距，有效地解決了相位法測距中測程與測量精度之間的矛盾，具有高精度、大量程、大噪聲容限的特點，而且簡化了硬體設計，降低了成本；其次在數據處理中採用數據加窗函數的方法，提高了方波信號的頻譜解析度，進而提高了測量的精度。
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