Research Of Adaptive CCCII- OTA Filter

Adaptive filter has been given high evaluation by a wide range.Such as communication field as echo cancellation, automatic equalization aspects, forming beam array of antenna. In this paper, the full study is currently at home and abroad for various types of adaptive filter implementation method based on adaptive stage filter for analog signal processing speed is not high, band width is not high, filter frequency automatic tracking and other issues can not be achieved, the researchers designed a species pass band can change with the input signal frequency, This waft has wide of frequency change range, analog signal processing is high-speed and adaptive filtering CCCII-OTA multifunctional filters.Focus on solving the problem: study based on a high-performance filter design theory current transfer controller, signal processing circuit speed is used by the current analog, bandwidth, etc; research using DSP implementation of wideband frequency voltage conversion circuit, solve the general F/I low-voltage converter chip frequency signal frequency, slow speed, in order to achieve the high frequency of self-tracking filter.The article is summarized and the majority of contents has several aspects:(1) Read a lot of domestic and foreign references, describes the importance of adaptive filters, functions, development prospects, while the simulation stage adaptive filter design methods summarized contrast, proposes high-performance F/I circuit combined with semiconductor transistor and FET design MCCCII and OTA current mode filter circuit design to solve the existing adaptive filter to track the frequency of low, slow, and only as a control variable voltage issue and realize the advantages of current variable.(2) Details of the characteristics and applications of current mode circuits are introduced each generation current conveyor, detailing introduction CCCII and OTA works principle and function, and in-depth study of the composition of the basic arithmetic circuit.(3) signal pre-processing circuit is Designed by this, frequency tracking circuit is designed, the same as,which includes shaping circuit, frequency measurement circuit, F/I circuit, automatic tracking this frequency signal, part of the circuit is simulated, the same as, measurements real circuits(4) MCCCII features designed to take advantage of different input order Universal different output filter formed by MCCCII, combined with the characteristics of OTA is designed multifunctional hybrid filter composed by MCCCII and OTA. Analysis theoretical and designed Cadence simulation filter, a part of the circuits have been measured by experimentallyThis design based CCCII and OTA of CCCII-OTA achieve adaptive filter pass-band can be dynamically adjusted with the input signal frequency is changed, the filtering frequency adaptive function. Measured the frequency and applied to the circuit, analysis frequency, harmonic is analysis, signal is detected, this circuit has important theoretical significance, it has application evaluation.