Peak gain and IP3 of a common-emitter amplifier

In summary, the conversation discussed how to calculate the peak gain in a small signal equivalent circuit by using basic electronics principles and possibly consulting a course book. The final result for the peak gain was -38.4, or 31.7dB.
  • #1
DavidEE
3
0
1. Homework Statement
Bildschirmfoto 2015-07-31 um 13.49.12.png

Homework Equations


Hi all.
Lets start with subquestion a).
How do i calculate the PEAK gain?

The Attempt at a Solution


I drew the small signal equivalent and calculated the gain: Av=vo/vi=-gm(ro//R=1kΩ//L//C)
Is that correct? How do i now calculate the peak gain?

Thank you for you help!
 

Attachments

  • upload_2015-7-31_13-53-8.png
    upload_2015-7-31_13-53-8.png
    26.7 KB · Views: 477
Physics news on Phys.org
  • #2
DavidEE said:
1. Homework Statement

Homework Equations


Hi all.
Lets start with subquestion a).
How do i calculate the PEAK gain?

The Attempt at a Solution


I drew the small signal equivalent and calculated the gain: Av=vo/vi=-gm(ro//R=1kΩ//L//C)
Is that correct? How do i now calculate the peak gain?

Thank you for you help!
It seems like the best bet would be to look in a basic electronics book. Like for example your course book. You kinda like read the thing, follow through some of the worked examples. Sometimes you get stuck and you have to reread a section a few times or check something on the internet. You are wasting your own time if you really believe you can get through a technical course without reading anything. It would be better to enter the workforce straight away if you can't/won't do the basics. Flip the burgers or read the books. 18+ you're an adult. Mom and pop can't buy you a great job.
 
  • #3
Wow, that was helpful, thanks!
 
  • #4
David - do you really mean R||L||C ? Which dimension do you expect as a result?
Have you heard already about the term "resonance"?
 
  • #5
I mean R||sL||1/sC.
r0 can be neglected.
That would result in jwRL/(R-w^2RCL+jwL).
The peak gain would be at w=1/sqrt(LC)? (Thanks LvW)
After some calculations i get Av=-gmR=-(Ic/Vt)R= -38.4, IAvI=31.7dB
 
  • #6
Yes - the result looks OK (for case a).
 

What is peak gain?

Peak gain refers to the highest amplification that can be achieved by a common-emitter amplifier. It is typically measured in decibels (dB) and represents the ratio of the output voltage to the input voltage at the point where the amplifier begins to distort the signal.

What factors affect the peak gain of a common-emitter amplifier?

The peak gain of a common-emitter amplifier can be affected by several factors, including the biasing of the amplifier, the type and characteristics of the transistors used, and the impedance of the input and output circuits.

What is IP3 and how does it relate to a common-emitter amplifier?

IP3, or the third-order intercept point, is a measure of linearity in an amplifier. In a common-emitter amplifier, IP3 represents the input signal level at which the third-order harmonic distortion is equal to the fundamental signal. A higher IP3 value indicates a more linear amplifier.

How do you calculate the peak gain of a common-emitter amplifier?

The peak gain of a common-emitter amplifier can be calculated using the formula: PG = 20log(Vout/Vin), where Vout is the peak output voltage and Vin is the peak input voltage. This calculation assumes that the amplifier is operating in its linear region.

Why is it important to measure the peak gain and IP3 of a common-emitter amplifier?

Measuring the peak gain and IP3 of a common-emitter amplifier is important for ensuring that the amplifier is operating within its desired range and producing accurate amplification of the input signal. It also helps in troubleshooting any potential issues with the amplifier's performance and in comparing the performance of different amplifiers.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
7
Views
890
  • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
29
Views
4K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
963
  • Engineering and Comp Sci Homework Help
Replies
17
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
3
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
7
Views
4K
  • Engineering and Comp Sci Homework Help
Replies
3
Views
2K
Back
Top