Filters that are Active are designed to remove unwanted frequencies and signals from a circuit using passives components and amplifying components. The filter types include Antialiasing, Band Pass, Bessel, Butterworth, Cauer, Continuous Low Pass, Digital, Elliptic Band Pass, FIR, Half Band, Linear Phase, Low Pass, Ripple, SD/ED/HD, Serial I/O, Universal, and Variable with frequency ranging from 2kHz to 6.9GHz.