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.

Whats the minimum NF for a CMOS LNA for 2.4GHz?

Status
Not open for further replies.

drabos

Full Member level 6
Full Member level 6
Joined
Jan 3, 2006
Messages
397
Helped
45
Reputation
90
Reaction score
15
Trophy points
1,298
Activity points
3,769
NF for LNA

Hello,

What's the minimum NF(Noise Figure) for a CMOS LNA for 2.4 GHz nowadays? (for example using 0.18 um CMOS technology)
Has anybody any idea?
What could the technology nowadays?
 

Re: NF for LNA

I've found a NF=3 dB LNA in 900 MHz. Could somebody a better value?
 

NF for LNA

Hi

I have designed a 1.8 dB NF LNA for WLAN 2.4-2.5 GHz in 0.18 um Si CMOS. The measured NF was around 2.6 dB (indirect measurement).
Some SiGe process based LNA (MAXIM) for 2.4 GHz may have lower NF but thats a trade-off.
Regards
Maddy
 

    drabos

    Points: 2
    Helpful Answer Positive Rating
NF for LNA

Hi.
It depends on what kind of topology you are using. For 2.4Ghz, I have seen NFs around 2.5dB for differential and 1 dB for single-ended. I have designed a differential LNA with 2.8dB NF.
 

    drabos

    Points: 2
    Helpful Answer Positive Rating
NF for LNA

Yes Suhas is absolutely right. A lot depends on the full set of specs like power consumption, Gain, linearity etc.
Maddy
 

    drabos

    Points: 2
    Helpful Answer Positive Rating
Re: NF for LNA

For WLAN where you do not have big blockers the lna can have a lot of gain so the noise figure can be low. At 0.18um cmos a NF of 1.5dB is fesable. The input network Q will be high which can effect linearity as well as component variation sensitivity.
 

    drabos

    Points: 2
    Helpful Answer Positive Rating
Re: NF for LNA

maddy said:
Hi

I have designed a 1.8 dB NF LNA for WLAN 2.4-2.5 GHz in 0.18 um Si CMOS. The measured NF was around 2.6 dB (indirect measurement).
Some SiGe process based LNA (MAXIM) for 2.4 GHz may have lower NF but thats a trade-off.
Regards
Maddy


What's the indirect measurement?
 

NF for LNA

We used the Y-Factor method as the Spectrum Analyzer we used didnt have the Noise Figure personality and the Noise Figure meter. The shift in the noise floor is measured with the Noise Source (connected to the DUT) on and off. Then using a formula, the NF is calculated. This link below gives a brief overview. There is a appnote on NF measurement on Agilent website.

https://www.tutorialsweb.com/rf-measurements/noise-figure/noise-figure-measurement-techniques.htm

Rgds
Maddy

Added after 56 minutes:

*.. We didnt have a Noise figure meter.
 

    drabos

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

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top