Designing first order Butterworth low pass filter

hey there... i've got question regarding 1st order butterworth filter...
i'm using Multisim software..

Question..

Design a first order Butterworth low pass filter with cut-off frequency fo = 20 kHz and the gain K = 1. You will need to simulate the circuit using Multisim and shows that the circuit meet the required specification.

i)Show all calculations steps and assumption made in your circuit design.
(URL provided)

ii)Show the circuit schematic with all the resistor and capacitor values labelled.(URL provided)

iii)Perform frequency response analysis on the circuit and obtain the bode diagram. The bode diagram should show the voltage gain (Vout / Vin) in dB vs the signal frequency (0 to 100 MHz). Does the -3dB cut-off frequency match the desired cut-off frequency fo = 20 kHz ? Explain. From the graph, estimate the roll-off rate. (URL provided)


https://i99.photobucket.com/albums/l313/nameck_5/Question2As.jpg
https://i99.photobucket.com/albums/l313/nameck_5/Question2a.jpg
https://i99.photobucket.com/albums/l313/nameck_5/Question2graph.jpg

Better go to your desk and try to do your homework by yourself. You have no doubts, you only want somebody do your homework for you.
BTW if you are unable to analyze a 1st order butterworth... back to the basics.

i've done it already.. but.. i need someone to varified my works.. =)




Question..
From the graph, estimate the roll-off rate.
how am i going to solve this question?[/img]

Hi naspek

Q:Question..
From the graph, estimate the roll-off rate.
how am i going to solve this question?

I suppose, you are able to derive from the picture the gain decrease per decade.
However, my point is another one:
Who ever gave you this task - ask him if he knows what a Butterworth filter is.
If he does not know, tell him that it has as a minimum a conjugate-complex pair of poles, which means it is at least of second order. (Butterworth and first order is nonsense!).

LvW said:

I suppose, you are able to derive from the picture the gain decrease per decade.
.

Click to expand...

i still not understand..

Very funny, we don't have first order butterworth filter.