A new 2nd order variable-state filter: The frequency agile filter

This article presents a new second-order state variable filter including two amplifiers. The centre frequency of the resulting filter, f
₀
, can be easily controlled using the gains of the amplifiers. This leads to a frequency-agile filter, whose centre frequency can be controlled over a wide range, without incidence on the power consumption. Simulation results given in this article confirm the new approach.