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.

中文翻译：

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用于低频应用的基于电感和电容的有源窄带滤波器

大多数工作在千赫兹频率范围内的模拟滤波器解决方案都基于 RC 元件。但是，使用这种架构无法设计非常窄的滤波器（大约 1000 的高 q 因子）。在本文中，我们将展示基于简单串联 LC 谐振电路（仅由电感器和电容器组成）和模拟电路实现的滤波器。基于这些元件设计的滤波器比基于 RC 元件（电阻器和电容器）的典型有源滤波器更具选择性。执行的测量证实了滤波器的正确操作，其中设计的滤波器 q 因子在 4.73 kHz 的谐振频率下为 ~591。