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

How to improve phase noise of an oscillator

Status
Not open for further replies.
G

geozog86

Member level 3
Member level 3
Joined
Oct 24, 2010
Messages
54
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
1,774
Hello!

In cadence simulations, i got the basic components that create the phase noise of my oscillator:
-the biasing block seems to be the most responsible one (45% of the noise) , but how does that make any sense? It's a PTAT generator from which all currents are mirrored, but it's not in one of the crucial nodes for the oscillation frequency.
-some transistors in the biasing current source are responsible via their id and some via their fn. What does that imply?
-how can i improve the phase noise? As a general approach? I can only guess higher current? Is there any other general approach?

Thx for the help :)
 

Re: Phase Noise Question

the noise from the bias devices can be mirrored to the main oscillating circuit causing poor phase noise.
add capacitor to ground/vdd on your bias nodes to act as a filter (you can implement gm-C filters also) this will help you reduce your flicker noise from the bias device by filtering.
increase your device sizes to decrease your noise, and increase current if available.
 
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top