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.

Hi, could recommend some equipments to measure phase noise?

Status
Not open for further replies.

dog1357

Member level 3
Joined
Dec 17, 2004
Messages
62
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,286
Activity points
531
Hi, could recommend some equipments to measure phase noise?

For very low phase noise like -160 dBc/Hz with some offset frequency.

Thank you.
 

vfone

Advanced Member level 5
Joined
Oct 10, 2001
Messages
5,293
Helped
1,549
Reputation
3,099
Reaction score
1,156
Trophy points
1,393
Activity points
33,546

elkimhoc

Member level 3
Joined
Apr 24, 2004
Messages
57
Helped
12
Reputation
24
Reaction score
9
Trophy points
1,288
Activity points
370
Re: Hi, could recommend some equipments to measure phase noi

HP 11729c + HP 8663A

or HP 3048A phase noise measurement
 

biff44

Advanced Member level 5
Joined
Dec 24, 2004
Messages
4,900
Helped
1,360
Reputation
2,716
Reaction score
1,039
Trophy points
1,393
Location
New England, USA
Activity points
36,869
Re: Hi, could recommend some equipments to measure phase noi

160 dBc/Hz at what offset frequency?
 

dog1357

Member level 3
Joined
Dec 17, 2004
Messages
62
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,286
Activity points
531
at an offset frequency roughly 20MHz
 

biff44

Advanced Member level 5
Joined
Dec 24, 2004
Messages
4,900
Helped
1,360
Reputation
2,716
Reaction score
1,039
Trophy points
1,393
Location
New England, USA
Activity points
36,869
Re: Hi, could recommend some equipments to measure phase noi

160 dBc/Hz is low, but at 20 MHz offset it is readily obtainable in the measurement schemes the others have stated above.

You can use a good spectrum analyzer that has a phase noise measurement utility.

Alternately, you can use a phase noise measurement system in conjunction with a tunable frequency synthesizer that is used to downconvert the unit under test to baseband. This is a more complex measurement, but is more accurate. The tunable frequency synthesizer that you use in this method has to have phase noise that is at least 10 dB better than the phase noise level you are trying to measure to.
 

Mazz

Advanced Member level 2
Joined
Nov 3, 2001
Messages
676
Helped
131
Reputation
262
Reaction score
50
Trophy points
1,308
Activity points
5,463
biff44

you cannot use spectrum analyzer for Phase noise measurement of 160 dBc, it's limited by its dynamic range not more than 155 dB in high end Agilent or R&S.
There is a possibility to do that with spectrum + notch + LNA setup (filter the carrier and amplify the noise with LNA), but it's a complex setup.
Latest VCO/PLL meter has this capability, but it's at the limit of its performance, can obtain it only with corrections (already implemented).

It's important ot note if you're interested in phase noise effects only or also to am/fm effects: with spectrum you cannot distinguish phase noise from am/fm conversion, you measure both; with dedicated phase noise testers, as they are based on a completely different way of measurements, you measure only phase noise.
I hope it can help.
Mazz
 

biff44

Advanced Member level 5
Joined
Dec 24, 2004
Messages
4,900
Helped
1,360
Reputation
2,716
Reaction score
1,039
Trophy points
1,393
Location
New England, USA
Activity points
36,869
Re: Hi, could recommend some equipments to measure phase noi

Mazz, you are right. I just tried a manual measurement on an older HP S/A, and all I got down to was -135 dBc/Hz while keeping the carrier uncompressed. Agilent says they can do -145 dBc/Hz at 1 GHz using the phase noise measurement utility:
https://www.home.agilent.com/USeng/nav/-536897871.536881858/pd.html

I guess you have to bite the bullet and rent a full blown phase noise measurement system, OR like Mazz says, switch in a notch filter and calibrated RF amplifier when you are measuring noise at 1 MHz+ from the carrier.
 

elkimhoc

Member level 3
Joined
Apr 24, 2004
Messages
57
Helped
12
Reputation
24
Reaction score
9
Trophy points
1,288
Activity points
370
Re: Hi, could recommend some equipments to measure phase noi

It not interesting to measure phase noise -160 dBc/Hz at 20 MHz offset from the carrier it so far, and it is a noise floor.
we measure oscillator phase noise from about 10 KHz.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top