I'm trying to create a Bode plot for the transfer function for a Multiple Feedback Filter. It's a frequency sensitive filter.
The problem is, my bode plot does not have the correct resonant/midfrequency which should be 1000Hz.
I know my transfer function is right because it can be found elsewhere online and using online bode plotters spits out my own transfer function and the correct Bode plot.
R_1 = 1500;
R_2 = 3300;
R_3 = 12000;
C = .047*10^-6;
s_numerator = -1/(R_1*C);
s2_denom = 1;
s1_denom = 2/(R_3*C);
s0_denom = (1+(R_1/R_2))/(R_1*R_3*(C^2));
H1 = tf ([s_numerator 0],[s2_denom s1_denom s0_denom])
I know H1 gives me the right transfer function but then when I use the bode operation on H1 the plot is all messed up.
MATLAB transfer function and Bode plot:
As you can see, the Bode plot is not centered at as it should be.
Graphed online using OKAWA Electrical Design:
As you can see, the band pass is centered at 1kHz as it should be and its transfer function is nearly the same transfer function as MATLAB gave me:
What is wrong with my MATLAB code?