Single VDGA-Based Mixed-Mode Electronically Tunable First-Order Universal Filter

Area of Science:

• Electronics Engineering
• Analog Circuit Design
• Signal Processing

Background:

• First-order universal filters are fundamental in signal processing.
• Existing designs often lack mixed-mode operation or electronic tunability.
• The voltage differencing gain amplifier (VDGA) is a versatile active component for circuit synthesis.

Purpose of the Study:

• To propose a novel mixed-mode, electronically tunable first-order universal filter.
• To demonstrate the realization of all standard filter functions (LP, HP, AP) in four operational modes (VM, TAM, CM, TIM).
• To achieve electronic tunability of pole frequency and passband gain.

Main Methods:

• Circuit design using one VDGA, one capacitor, and one grounded resistor.
• Analysis of non-ideal and parasitic effects.
• Validation through PSPICE simulations and experimental measurements.

Main Results:

• The proposed circuit successfully implements LP, HP, and AP functions in VM, TAM, CM, and TIM.
• Electronic tunability of pole frequency and gain is achieved by adjusting transconductance values.
• Simulations and experimental results confirm the circuit's performance and practical viability.

Conclusions:

• The presented mixed-mode electronically tunable filter offers a simple and flexible solution.
• The design's ability to realize multiple functions and modes from a single structure is a significant advantage.
• The validated performance makes the proposed configuration suitable for practical electronic applications.