Design and Simulation of Subsonic Frequency, Frequency-Selective Circuit Using Active Inductor

Designing very low frequency (VLF) tuning circuits poses a significant challenge due to the impractical size of inductors required at these frequencies. As the frequency decreases, the inductance value needed becomes larger, making it difficult to implement physically. To address this issue, this paper presents an alternative approach that replaces the traditional passive inductive component (L) with a simulated inductor. The simulated inductor, designed specifically for VLF applications, offers a practical solution to overcome the limitations of using large inductors. The design of the simulated inductor is explained in detail, and its application in VLF tuning circuits are demonstrated. By replacing physical inductors with simulated counterparts, the circuit's size is significantly reduced, while maintaining the desired frequency-selective characteristics. The simulation of the designed circuit is carried out using PSPICE, an analog simulation software. The performance of the simulated inductor in tuning circuits are evaluated, and the results are graphically represented using Python. These simulations provide valuable insights into the effectiveness and accuracy of the proposed method in replicating the behaviour of large inductors at very low frequencies. The results confirm that simulated inductors offer a viable solution for VLF circuit design, reducing component size without sacrificing performance. This approach is expected to benefit various applications where size constraints and frequency selectivity are critical.