公开(公告)号：US3831103A

公开(公告)日：1974-08-20

申请号：US35589073

申请日：1973-04-30

Applicant: BECKMAN INSTRUMENTS INC

Inventor： RUEGG F ,  SILVA L

IPC: H03H11/12 ,  H03F1/36

CPC classification number: H03H11/1295

Abstract: An active element sharp cut-off bandpass filter circuit having independently tunable center frequency and Q characteristics. The filter circuit incorporates a high performance operational amplifier having one input connected to ground and a pair of feedback paths interconnecting the amplifier output and the other input. One feedback path includes two capacitors connected in series and the other path includes two resistors connected in series. The input to the filter circuit is connected, via an input resistor, to the common juncture of the capacitors; and the amplifier output is connected to the filter output terminal, as well as to one end of a grounded voltage divider having a movable tap. The common juncture of the feedback resistors is connected, via a capacitor, to the movable tap of the voltage divider. In one embodiment the capacitors have equal values and the feedback resistors have values which are four times the value of the input resistor.

Abstract translation: 具有独立可调的中心频率和Q特性的有源元件尖锐截止带通滤波器电路。 滤波器电路包括具有连接到地的一个输入的高性能运算放大器和互连放大器输出和另一个输入的一对反馈路径。 一个反馈路径包括串联连接的两个电容器，另一路径包括串联连接的两个电阻器。 滤波电路的输入通过输入电阻连接到电容器的公共接点; 并且放大器输出连接到滤波器输出端子，以及连接到具有可移动分接头的接地分压器的一端。 反馈电阻的共同接点通过电容器连接到分压器的可移动抽头。 在一个实施例中，电容器具有相等的值，并且反馈电阻器的值是输入电阻器值的四倍。