I am trying to design a filter which has the following Bode plot,
So according to this site I designed the filter as shown below,
As the two cross over frequencies are f1 = 50 Hz and f2 = 200 Hz, I did the following calculation for R1 and R2
Assuming C= 0.1uF and using f1 = 1/(2*Pi*R1*C), I calculated R1= 31.83 Kohm
In order to calculate R2 I first calculated the Gain= f1/f2 = 0.25
So, now again using Gain= R2/(R1+R2), I calculated the value of R2 = 10.61 Kohm
So, in order to check i did a quick simulation in LTspice, here is what I did.
But I am not sure if it is right,in question it says that the sloop between f1 and f2 is -6dB but in the simulation the magnitude plot is started from -12dB, I would expect it to start from -6dB.
Also about the input and output impedance, how do I make sure the o/p impedance is greater than 10 Kohm and input impedance is less then 100 ohm? Does this has something to do with the value of R1 and R2?