RF Electronics Symbols, Stencils for Office, Visio by RF Cafe
LadyBug Technologies LB5944A RF Power Sensor - RF Cafe
 

About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

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

Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes App Notes Calculators Education Engineering magazine articles Engineering software Engineering smorgasbord RF Cafe Archives RF Cascade Workbook 2018 RF Symbols for Visio - Word Advertising RF Cafe Homepage Thank you for visiting RF Cafe!
everythingRF RF & Microwave Company Directory (h) - RF Cafe

Drain current vs. Sweep output power - RF Cafe Forums

RF Cafe Forums closed its virtual doors in 2012 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. If the folks at phpBB would release a version with integrated sign-in from the major social media platforms, I would resurrect the RF Cafe Forums, but until then it is probably not worth the effort. 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
-- Antennas
-- CAE, CAD, & Software
-- Circuits & Components
-- Employment & Interviews
-- Miscellany
-- Swap Shop
-- Systems
-- Test & Measurement
-- Webmaster

Jeanalmira
Post subject: Drain current vs. Sweep output power Posted: Mon Sep 19, 2005 5:06 am

General


Joined: Tue Mar 15, 2005 11:43 pm
Posts: 65
Location: Singapore
Hi all :

I have one question regarding drain current at sweep output power. I understand that at most cases, drain current will increase as output power increases. However, I encountered it is the other way round. The drain current decreasing as output power increases. Why is it so?

I'm sweeping the output power in lower region than saturation power.
and I'm sweeping dual-tone input power (for IM3 measurement).

Can anybody enlighten me?

Any advice is appreciated.

Thanks and Regards,
Jean


Top

Guest
Post subject: RF Power SweepPosted: Mon Sep 19, 2005 11:50 am
The last time I saw something like that was at lower frequencies, but the amplifier needed neutralization - it was not very stable.

Hope this helps.

Good Luck!


Top

Jeanalmira
Post subject: Posted: Mon Sep 19, 2005 8:27 pm

General


Joined: Tue Mar 15, 2005 11:43 pm
Posts: 65
Location: Singapore
Hi :

Thanks for your advice
By the way, the PA (3-stages) frequency range is 1.8GHz, and sweep Pout is from 17dBm to 27dBm, while the estimated P1dB >35dBm.

and the PA is unconditionally stable at this frequency range as K>1, |S11|<1 and |S22|<1.

So I'm not sure why the current decreasing when Pout increases?

Any advice is appreciated.

Thanks and Regards,
Jean


Top

Guest
Post subject: Posted: Tue Sep 20, 2005 8:56 am
One possibility is that there is resistance on the bias lines. As the power increase, the current increases, droping more voltage therefore turning the amplifier down. Check the voltage at the input of th amplifier to make sure that the bias voltage you think is there actually is.



Posted  11/12/2012
Werbel Microwave - RF Cafe
Axiom Test Equipment - RF Cafe
 

Please Support RF Cafe by purchasing my  ridiculously low−priced products, all of which I created.

These Are Available for Free