Cascaded higher order filter with low sensitivity to component values and a method for designing the same

摘要

The present invention provides a higher order filter with low sensitivity to component values and to a method of designing the same. The higher order filter is constructed of second and/or third order filter circuits which have been desensitized with respect to component values and gain by impedance tapering the filter circuits. The filter circuits are impedance tapered by successively scaling the resistors and/or capacitors from left to right to minimize loading on the first filter section and to maximize the quality factor of the passive pole. The impedance of the filter sections is increased from left to right by increasing the resistor values and/or by decreasing the capacitor values from left to right. Once the lower order filter circuits have been designed, they are cascaded to provide a higher order filter with low sensitivity to component values and gain.