Patent ID: 8710921

Claim:
A continuous time filter of at least a second (or higher) order, comprising: one or more first order filter stages of a first type, each first order filter stage of the first type comprising a reactive component and an impedance of a first type, the impedance of the first type being such that a first current therethrough is dependent on the difference between the input and output voltages of the filter stage; at least one first order filter stage of a second type, each first order filter stage of the second type comprising a reactive component and an impedance of a second type, the impedance of the second type being such that a second current therethrough is dependent on the sum of the input and output voltages of the filter stage, the impedance of the second type being realized by arranging a pair of transistors in cross-diode connection; wherein a transfer function of the continuous time filter is obtained comprising complex poles.