【導讀】20世紀50年代無源濾波器日趨成熟。70年代以后的主攻方向。凡是有能力進行信號處理的裝置都可以稱為濾波器。在近代電信設備和各類控制系。濾波器的優(yōu)劣直接決定產(chǎn)品的優(yōu)劣，所以，對濾波器的研究和生產(chǎn)歷來為各國。速發(fā)展，到70年代后期，上述幾種濾波器的單片集成已被研制出來并得到應用。代，致力于各類新型濾波器的研究，努力提高性能并逐漸擴大應用范圍。主要致力于把各類濾波器應用于各類產(chǎn)品的開發(fā)和研制。我國廣泛使用濾波器是50年代后期的事，當時主要用于話路濾波和報路濾波。按處理信號類型分類，可分為模擬濾波器和離散濾波器兩大類。1965年單片集成運算放大器問世后，為有源濾波器開辟了廣闊的前景。由于運放的增益和相移均為頻率的函數(shù)，這就限制了RC有源濾波器的頻率范圍，成工藝不過關，并沒有引起人們的重視。引起人們的重視。SCF的應用以聲頻范圍應用為主體，工作頻率在100kHz之內(nèi)。1983年清華大學已制成單片SCF，成都工程學院與工廠聯(lián)合，也研

　　

【正文】 ore road between TDM/FDM signal transformation after meet... (3) The multidimensional DF In image processing, earthquake, oil exploration data processing all use multidimensional DF (monly used is 2 d DF), the design of the multidimensional DF, often a d DF optimization design to multidimensional DF direct marketing. For fuzzy and random noise interference 2 d image processing, multidimensional DF also can play a very good effect. In addition, still wave DF, it is easy to realize largescale integrated, facilitate passive and active power filter work digital simulation. Therefore, is attention by people and studied. For DF remains to be subjects of study: coefficient sensitivity, rounding noise and limit cycle, the stability of the multidimensional inverse to filter, all kinds of hardware and software implementation of DF research and so on. In short, DF in digital signal processing technology is very important position in possession, for its research, production and application, etc all is very meaningful. 7, Other new filter In order to adapt to all kinds of need, the emergence of a batch of new filter, presented here has been widely used several types of filters. (1) Electric control programming CCD horizontal filter (FPCCDTF) A chargecoupled device (CCD) fixed weighted transverse filter (TF) in signal processing, the performance and cost all can with digital filter and all kinds of signal processing unit). This filter is mainly used for adaptive filter。 PN sequence and Chirp waveform of matched filter。 Generalization of frequency domain filter and related product operation。 Speech signal and the phase equilibrium。 Phase array systems beam synthesis and television signals (2) Cystal filter It is to meet with the single technology and developed. In the 1970 s, the integrated production of crystal filter, make it of development have a leap. In the last ten years, crystal filter below to some research: to achieve the best design, besides having the fine choose outside, still have good time domain response。 Seek new materials。 Extended working frequency。 Modification technology, made it to the integrated development. It is widely used in multiplexed system as the carrier filter, in sending and receiving the letter, with the single munication machine as frequency selective filter, in a spectrum analyzer and sonar device as intermediate frequency filters. (3) Surface acoustic filter It is the ideal uhf devices. Its amplitude frequency characteristics and phase characteristic respectively control, so as to meet the requirements, and it also has small volume, long time good stability and simple process etc. Characteristics. Usually used in: TV broadcast transmitter as residual sideband filter。 The color television receivers of tuning system surface b form filter. In addition, in the defense satellite munication systems has been widely adopted. Surface acoustic filter is electronics and acoustics product of integration of, and can be integrated, so, it all passive filter in the most promising. Various new filter too is various, somewhere, no longer described them. Our country at present the application of various filter proportion Our country39。s existing types of filters and the frequency of the covered has basically satisfy existing telemunications equipment. From the overall, our country active filter development than passive filter slow, has not been a lot of production and application. From the following production application proportion of various types of filters can be seen, the application of the: LC filters 50%。 Crystal filter accounted for 20%。 Mechanical filter accounted for 15%。 Ceramic filter harmonic surface each accounted for 1%。 The rest accounted for 13% of all kinds of filter. From the application scale, electronic products in China to realize the largescale integrated, filter integration is still a important topic. Along with the development of the electronic industry, to filter the performance requirements of more and more high, function more and more, and asked them to integration development direction. Our country filter development and production of the above requirements and far, in order to reduce that gap, electronic engineering and scientific and technological personnel responsible for the major historical responsibility.