transistor frequency response

[karthickb3e]

what is the easiest way to determine and analyze the frequency response of transistor amplifiers......

please give solution steps

 

[milind.a.kulkarni]

If you want to do this you need to have a signal generator with gain adjustment-

Follow the following steps-
1) Read the data sheet of the transistor. That will tell you the bandwidth and frequencies that you can use for the transistor
2) Then you need make a transistor circuit for amplifier
3) Set some voltage for siganl generator and lowest frequecy that you can set ....Start giving the signal input to the amplifer that you are designed....
4) Measure the wave form and it peak voltage at the output stage of your amplifier.....
5) Start increaming the the requency of singal generator with integral multiple of the some constast like 100Hz(initial set), then like 400Hz steps like 100Hz, 500 Hz, 900 Hz, 1.3Khz....upto maximum frequency specified in the data sheet.... Kindly please note that voltage that you set on the signal generator should not change....otherwise results will not be accurate
6) You will observe the attenuation at the starting frequecies and near to maximum frequencies....
7) You can find out the parameters like bandwidth ( range of frequencies lies for 0.707 of the peak amplification), gain bandwidth product etc...

Good Luck

 

[karthickb3e]

i am new to design...... how to make the above steps in circuit simulator(orCAD).......
is this possible.. help me.......!

 

[santom]

Thanks Mr.Kulkarni..that was a verd good explanation

 

[cks3976]

Draw the Transistor amp circuit in Spice (Orcad) and use AC/Sweep analysis for plotting the response. You will have to specify a sweep frequency range to obtain the plot.