Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

The condition for start up of oscillation

Status
Not open for further replies.
S

slienteyes

Junior Member level 2
Joined
Mar 17, 2006
Messages
21
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,420
It seems very complex to understand the condition for start up oscillation. I found the comment in ADS tutorial: It follows from the Nyquist criterion that the presence of poles in the right-half plane and the system instability can be determined by the encirclements of point 1+j0 by the osctest generated contour S11 = Sr(jw)Sn(jw). What's the meaning for the condition?

In Ganzales book, the comment seems different.
 

It's another way of saying stability factor for that specific circuit is smaller than 1
k<1
This means reflection coefficient is greater than 1, where the circuit presents a negative input resistance. The wave reflected off a positive resistance load would be smaller than the incident wave. However, if the Re{ZL} < 0, then it would be possible for Γ in to be greater than 1. so, always reflected waves becomes larger than incident waves. This causes an oscillation to begin.

Best regards,
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top