Single amplifier functionally tunable low-pass-notch filter

The canonical network developed in this paper is an active RC negative feedback arrangement that uses a single op-amp and two capacitors to realize low-pass-notch filter characteristics. The filter parameters are adjustable through resistive trimming. This functional tuning process uses a signal generator, a dB-scale voltmeter and a phase meter. The analytical design procedure takes into account a single-pole amplifier model. The network has low-passive sensitivities and is suitable for moderate-
Q
applications (
Q \leq 5
). An example is discussed giving the resistor's limits for a
\pm
10 percent capacitance tolerance.