Select installation and then antenna setting , and set respectively the local oscillator frequencies of the high - frequency tuner of 146 , 138ku , 138c band and so on 選擇安裝里的天線設(shè)定,分別設(shè)置146 、 138ku及138c波段等等的高頻頭本振頻率。
The phase detecting error caused by local oscillator frequency drift and non - synchronization of measurement signal and gate signal is eliminated and the measurement speed is improved at the same time 該方法可以有效的消除因本振信號頻率漂移及閘門信號與被測信號的非同步引起的測相誤差,同時提高了測量速度。
Article has introduced partition and the definition of oscillator frequency stability , and analyzed emphatically to cause the vibration factor with instability frequency , this paper elaborated the major measure and steady method that how to raise frequency stability 摘要介紹了振蕩器頻率穩(wěn)定度的定義與劃分,著重分析了導(dǎo)致振蕩頻率不穩(wěn)定的因素,詳細(xì)地闡述了提高頻率穩(wěn)定度的主要措施和穩(wěn)定方法。
At present , there are various methods of moving vehicle detector and identification . the system we designed for traffic information makes use of the principle of electromagnetic induction and radio frequency identification the moving vehicle detector , which is based on inductive circular loop , detects the information of vehicle according to the inductive signal . the basic information including speed and go through time can be detected to analyze oscillator frequency 目前現(xiàn)行的車輛檢測與識別系統(tǒng)的種類繁多,本系統(tǒng)基于電磁感應(yīng)理論和射頻識別技術(shù),采用環(huán)形線圈作為數(shù)據(jù)采集傳感器,通過對振蕩器的頻率計數(shù)測量到車輛的通過、速度等基本信息,同時啟動射頻識別系統(tǒng),使讀寫器與安裝在車輛上的非接觸ic卡進(jìn)行無線通訊獲取通過車輛的類型和所屬用戶等數(shù)據(jù),并將有關(guān)數(shù)據(jù)通過rs232串口送至上位機(jī)。
A full - digital demodulation technique is introduced in this paper , which can make it easy and quick to design and achieve binary phase shift keying ( bpsk ) demodulator , and also can reduce the requirement of the oscillator frequency precision and the degree of stability of the receiver 本文介紹了一種適合于用數(shù)字信號處理器( dsp )實(shí)現(xiàn)的全數(shù)字解調(diào)技術(shù)。該技術(shù)能方便、靈活地設(shè)計實(shí)現(xiàn)二進(jìn)制相移鍵控( bpsk )解調(diào)器,而且使用該技術(shù)可以大大降低對接收機(jī)本身的振蕩頻率精度和穩(wěn)定度的要求。