Hi all,

I was hoping someone might be able to provide some guidance/point me in the right direction for the below problem:

The objective is to design an active bandpass with the following parameters:

Centre frequency Fc = 100kHz

Bandwith fH -fL = 10kHz

So far I have the following:

Given that the bandpass filter has a Centre or Resonant Frequency of 100kHz and a Bandwidth Frequency (BW) of 10kHz I have approximated the lower and upper cut off frequency at 95kHz and 105kHz respectively.

BW = fH - fL => 105k - 95kHz = 10kHz

Assuming a nominal Resistor value of 1K for both LPF and HPF circuits the capacitance values can then be obtained.

C1 = 1/2π.fL.R1 & C2 = 1/2π.fH.R2

The values of which are 1.67nF and 1.51nF respectively. These values are inputted into the below non inverting bandpass circuit. Circuit Gain selected to be around 10

The output waveform derived from this configuration is as per below

As can be seen the output waveform is heavily attenuated and the calculated cut-off frequencies of 95k and 105k are thus not at 0.707 (-3db) at expected.

My question is how can this be configured so as to output the expected results at the appropriate frequencies?

Any advice guidance would be appreciated.

I was hoping someone might be able to provide some guidance/point me in the right direction for the below problem:

The objective is to design an active bandpass with the following parameters:

Centre frequency Fc = 100kHz

Bandwith fH -fL = 10kHz

So far I have the following:

Given that the bandpass filter has a Centre or Resonant Frequency of 100kHz and a Bandwidth Frequency (BW) of 10kHz I have approximated the lower and upper cut off frequency at 95kHz and 105kHz respectively.

BW = fH - fL => 105k - 95kHz = 10kHz

Assuming a nominal Resistor value of 1K for both LPF and HPF circuits the capacitance values can then be obtained.

C1 = 1/2π.fL.R1 & C2 = 1/2π.fH.R2

The values of which are 1.67nF and 1.51nF respectively. These values are inputted into the below non inverting bandpass circuit. Circuit Gain selected to be around 10

The output waveform derived from this configuration is as per below

As can be seen the output waveform is heavily attenuated and the calculated cut-off frequencies of 95k and 105k are thus not at 0.707 (-3db) at expected.

My question is how can this be configured so as to output the expected results at the appropriate frequencies?

Any advice guidance would be appreciated.

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