一款由cmos數(shù)字集成電路的構(gòu)成的定時(shí)器畢業(yè)論文(編輯修改稿)

　

【文章內(nèi)容簡(jiǎn)介】 參考文獻(xiàn)：楊素行、《模擬電子技術(shù)基礎(chǔ)簡(jiǎn)明教程》、北京：高等教育出版社賴(lài)金福、《數(shù)字集成電路簡(jiǎn)明手冊(cè)》、199北京：電子工業(yè)出版社黃繼昌、《數(shù)字集成電路應(yīng)用300例》、200北京：人民郵電出版社何希才、《新型集成電路及其應(yīng)用實(shí)例》、200北京：科學(xué)出版社龍忠琪、《數(shù)字集成電路教程》、200北京：科學(xué)出版社肖景和、《數(shù)字集成電路應(yīng)用精粹》、200北京：人民郵電出版社陳其純、《電子線路》、2000、北京：高等教育出版社康華光、《電子技術(shù)基礎(chǔ)》、200北京：高等教育出版社翁桂榮、《單片微型計(jì)算機(jī)原理》、200蘇州：蘇州大學(xué)出版社外文資料Radio Frequence and Microwave ApplicationIntroduction This chapter lays the foundation for understanding higherfrequency wave Phenomena and divides the task of active circuit design for RF/MW frequencies Into specific concept blocks. These concept blocks create a gradual approach to Understanding and designing RF / MW circuits and represent specific realms of Knowledge that need to be mastered to bee an acplished designer.Before we describe and analyze these types of waves we need to consider Why RF / Microw waves as a subject has bee so important , that it is placed At the forefront of our modern technology . Furthermore, we need to expand our Minds to the many possibilities that these signals can provide for peaceful practices by exploring various mercial applications useful to mankind.A Short History of RF and MicrowavesCirca 1864—1873 , James Clark Maxwell integrated the entirety of man’s Knowledge of electricity and magnetism by introducing a set of four coherent And selfconsistent equations that describe the behavior of electric and magnetic Fields on a classical level. This was the beginning of microwave engineering , as Presented in a treatise by Maxwell at that time . He predicted, purely from a Mathematical standpoint and on a theoretical basis , the existence of Electromagnetic wave propagation and that light was also a form of Electromagnetic energy —both pletely new concepts at the time .From 1885 to 1887 , Oliver Heaviside simplified Maxwell’s work in his Published papers. From 1887 to 1891, a German physics professor, Heinrich Hert , verified Maxwell’s predictions experimentally and demonstrated the Propagation of electromagnetic waves. He also investigated wave propagation Phenomena along transmission lines and antennas and developed several useful Structures. He could be called the first microwave engineer.Marconi tried to mercial radio at a much lower frequency for longDistance munications, but as he had a business interest in all of his work And developments, this was not a purely scientific endeavor.Neither Hertz nor Heaviside investigated the possibility of electromagnetic Wave propagation inside a hollow metal tube because it was felt that two Conductors were necessary for the transfer of electromagnetic waves or energy In 1897 , Lord Rayleigh showed mathematically that electromagnetic wave Propagation was possible in waveguides, both circular and rectangular. He Showed that there are infinite sets of modes of the TE and TM type possible ,Each with its own cutoff frequency .These were all theoretical predictions with No experimental verifications .From 1897 to 1936 , the waveguide was essentially forgotten until it was Rediscovered by two men , George South worth(ATamp。T) and . Barron(MIT) Who showed experimentally that a wave guide could be used as a small Bandwidth transmission medium, capable of carrying high power signals.With the invention of the transistor in the 1950s and the advent of Microwave integrated circuits in the 1960s, the concept of a microwave system On a chip bee a reality . There have been many other developments, mostly In terms of application mass , that have made RF and microwaves an Enormousely useful and popular subject. Maxwell’s equations lay the foundation And laws of the science of electromagnetics , of which the field of RF and Microwaves is a small subject. Due to the exact and allenpassing nature of These laws in predicting electromagnetic phenomena ,along with the great body Of analytical and experimental investigations performed since then , we can Consider the field of RF and microwave engineering a “mature discipline” at this Time .Applications of Maxwell’s Equations As indicated earlier in chapter 2 , Fundamental Concepts in Electrical and Electronics Engineering , standard circuit theory can neither be used at RF nor Particularly at microwave frequencies . This is because the dimensions of the device or Components are parable to the wavelength , which means that the phase of an Electrical signal (., a current or voltage) changes significantly over the physical Length of the device or ponent .Thus use of Maxwell’s equations at these higher Frequencies bees imperative . In contrast , the signal wavelengths at lower frequencies are so much larger than the Device or ponent dimensions , that there is negligible variation in phase across the Dimensions of the circuit . Thus Maxwell’s equations simplify into basic circuit theory ,As covered in chapter 3 , Mathematical Foundation for Understanding Circuits .At the other extreme of the frequency range lies the optical field , where the wavelength Is much smaller than the device or circuit dimensions . In this case , Maxwell’s equations Simplify into a subject monly referred to as geometrical optics , which treats lights as A ray traveling on a straight line .These optical techniques may be applied successfully to the analysis of very high Microwave frequencies (., high millimeter wave range) , where they are referred to as “quasioptical.” Of course , it should be noted that further application of Maxwell’s Equations leads to an advanced field of optics called “physical optics or Fourier optics ,”Which treats light as a wave and explains such phenomena as diffraction and interference ,Where geometrical optics fails pletely .The important conclusion to be drawn from this discussion is that Maxwell’s equations Present a unified theory of analysis for any system at any frequency , provided we use Appropriate simplifications when the wavelengths invovled are much l