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 can i sum PSD spectrum ?

Status
Not open for further replies.
D

drcham

Newbie level 5
Joined
Dec 19, 2007
Messages
10
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Russia, Moscow
Activity points
1,343
I have plotted two graphs of spectrum in rad^2/Hz (one vco ans second is amplifier)
How can i plot total noise from vco and amplifier ?
I've used to plot noise in dBc and i've calculated total as sqrt(sqr(x1(fm))+sqr(x2(fm))) and so on. Ca i sum PSD spectrum in the same way ?
 

I think they just add linearly in power. Assuming the two were uncorrelated, if VCO had a phase noise of -20 dBc/Hz at 1 KHz offset, and amplifier had -30 dBc/Hz at 1 KHz offset,

P = 0.01 + 0.001 = 0.011 which would look like -19.586 dBc/Hz at 1 KHz offset for the series combination of VCO and Amplifier.

Rich
 
Last edited by a moderator:
  • Like
Reactions: drcham

    D

    drcham

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top