Electronic filter circuit

Abstract From the Canadian patent

To eliminate the high frequency portion of an input signal while permitting low frequency and DC portions to pass the electronic filter utilizes, an n-l order active network in combination with a capacitor to generate 2 shunt current, thereby providing a low pass filter having n-order operating characteristics. Included in the active network is an active element such as, an operational amplifier, which responds to an input signal by creating a voltage across the capacitor resulting in a shunt current that in turn provides the desired filter characteristics. In certain special cases the n-order active filter can utilize a differentiating element in combination with an n-2 order active …