Voltage mode OTA based KHN filter

Second order filter structures have widespread applications. They are also used in realization of higher order filter. Among the second order filters, KHN (Kerwin, Huelsman, and Newcomb) filter is used as a reference while designing second order filters with other active elements. A new KHN filter, employing two OTA's, two ground capacitance and one resistance is proposed in this paper. The Q and cutoff frequency of the proposed filters are orthogonal and the cutoff frequency can be tuned without changing the passive components. This filter is verified by SPICE simulation.