Active narrowband filter based on inductance and capacitance for low-frequency applications

Most analog filter solutions operating in the kilohertz frequency range are based on RC elements. However, it is not possible to design a very narrow filter (high q-factor around 1000) by using this architecture. In this article, we would like to show a filter implemented based on a simple series LC resonance circuit (consisting of just an inductor and a capacitor) and an analog circuit. The designed filter based on these elements can be more selective than a typical active filter based on RC elements (resistor and capacitor). Performed measurements confirmed the correct operation of the filter, where the designed filter q-factor was ∼591 at a resonant frequency of 4.73 kHz.