Proteus在开关电阻调制跟踪滤波器设计中的应用

摘要

中心频率自动可调的跟踪滤波电路是一种应用广泛的带通滤波电路.提出了一种基于开关与电阻串联调制方法的跟踪滤波器电路实现方法.开关电阻支路通过适当的电路连接方式并以一定的方式控制开关的通断,可产生所需要的等效电阻.从能量等效的角度给出了开关电阻支路等效电阻的计算方法.讨论了基于开关电阻调制的跟踪滤波器设计方法.设计了双二次结构的带通跟踪滤波器,该电路由1片四运放芯片AD713、2片模拟开关芯片DG418以及若干电阻、电容元件组成.采用Proteus对跟踪滤波器的特性进行测试,其结果与理论分析吻合,为跟踪滤波器的实际应用提供了可靠的依据.%The tracking filter with automatically adjustable center frequency is a widely used band-pass filter circuit.A realization method of the tracking filter circuitis is proposed based on modulation of switching resistors.The desired equivalent resistance can be obtained through appropriate circuitry and control of switch mode.The equivalent resistance can be computed through energy equivalence theory.The design of tracking filter based on modulated switching resistors is discussed.A tracking filter with biquadratic structure is designed.The filter is composed of a four op-amp chip (AD713),two single-pole/single-throw analog switch chips (DG418) and some resistors and capacitors.Proteus software is applied to measure the characteristics of the tracking filter,and the simulation results coincide with those of theoretical analysis.The method provides a reliable basis for the application of the tracking filter.