3. Experimental results
To demonstrate the feasibility of the proposed circuit, the circuit in Fig. 1 is
implemented by using commercial CCIIs (AD844) (Analog Devices 1990). A second-
order notch filter is realized with Vin2 = 0, Vin1 = Vin3 = Vin, C1 = C2 = 1nF
and R1 = R2 = R3 = 10kV . Figure 4 shows the experimental results for a second order
notch filter. Experimental results confirm with the results of the theoretical
analysis.