Low power agile active filter with digitally controlled center-frequency

An agile active filter with digitally controlled center frequencies has been introduced in this paper. It is based upon a second-order filtering cell and several amplifiers. The resulting center frequency f₀ can then easily be tuned simply by adjusting the value of the gain of the amplifiers. From this results a filter with agile center frequency, which can be tuned over a very large frequency range. The presented simulation results validate this approach.