Innovative Power Products Couplers

measuring The Noise Figure of WLAN Receiver RF Front-end - RF Cafe Forums

RF Cafe Forums closed its virtual doors in 2010 mainly due to other social media platforms dominating public commenting venues. RF Cafe Forums began sometime around August of 2003 and was quite well-attended for many years. By 2010, Facebook and Twitter were overwhelmingly dominating online personal interaction, and RF Cafe Forums activity dropped off precipitously. Regardless, there are still lots of great posts in the archive that ware worth looking at. Below are the old forum threads, including responses to the original posts.

-- Amateur Radio

-- Anecdotes, Gripes, & Humor

-- CAE, CAD, & Software

-- Circuits & Components

-- Employment & Interviews

-- Test & Measurement

ashishbondia

Post subject: measuring The Noise Figure of WLAN Receiver RF Front-end

Posted: Thu Jan 21, 2010 7:31 am

Colonel

Joined: Wed Aug 16, 2006 8:20 am

Posts: 28

Location: India

Hi!

I want to measure the Noise Figure of the RF Front-end (Switch+LNA+Diplexer) for a WLAN receiver implemented using Discrete components.

I don't have a Noise source and Noise Figure meter to chatracterize the Noise Figure of this assembly. I was thinking of trying the following approach.

1. Since I don't have a vector signal generator, I will use a WLAN transmitter that I designed. Attenuate the output power to -60dBm (burst power). Feed this signal to a Vector Signal Analyzer and measure the EVM. Let us call the EVMin

2. Remove the VSA and connect the RF Receiver Front-end. This will feed the Transmitted signal at the antenna port of the Receiver. Now at the other end of the receiver chain connect the VSA and record the EVM. Let us say that this is EVMout.

3. Can I assume that the EVM will be proportional to the SNR at low input power levels. if yes, then can I use the difference between EVMin and EVMout as an estimate of the Receiver RF Front-end Noise Figure.

I will be trying this out in the LAB. If anyone finds any fault in this method thebn please share your thoughts.

regards,

Ashish Bondia

_________________

Ashish Bondia,

Design Engineer- RF

Posted 11/12/2012

Exodus Advanced Communications Best in Class RF Amplifier SSPAs


Please Support RF Cafe by purchasing my ridiculously low−priced products, all of which I created. RF Cascade Workbook for Excel RF & Electronics Symbols for Visio RF & Electronics Symbols for Office RF & Electronics Stencils for Visio RF Workbench (shareware) T-Shirts, Mugs, Cups, Ball Caps, Mouse Pads These Are Available for Free Calculator Workbook Smith Chart™ for Excel

About RF Cafe Copyright: 1996 - 2024 Webmaster: Kirt Blattenberger, BSEE - KB3UON RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived... All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged. My Hobby Website: AirplanesAndRockets.com