RIGOL Technologies (test equipment) - RF Cafe
LadyBug Technologies LB480A 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!
RF Electronics Shapes, Stencils for Office, Visio - RF Cafe

parallel feed back resistor - 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

Guest
Post subject: parallel feed back resistor Posted: Tue Aug 23, 2005 3:35 am
Hello!
Can any one explain how do we determine the safe value of parallel feed back resistor being used to level the gain and stabilize the device as well. My concern is the heat dissipation due to Rf energy. I am using it for various RF power out puts eg, 5W,10W etc.


Top

Guest
Post subject: Parallel Feedback ResistorPosted: Tue Aug 23, 2005 7:19 pm
One of the replies you hear a lot on this site is "what are the details of your application". The reason is that there are no totally general formulas or rules for anything - there are always trade-offs that get made differently, depending on the parameters of the situation. Feedback techniques appropriate for LNAs are not necessarily the techniques you'd use for an HPA.

Normally, you don't want to burn up too much power in resistors, regardless of where they are. If it's RF power you're burning up, that's pretty costly stuff!

So the questions are,
1. What frequency range are you talking about?
2. What kind of circuit are you talking about? That's important because if you need to stabilize a circuit, you already have feedback - and you've got to know the nature, amount, and effects of that feedback.
3. Are there any other objectives? Linearity: harmonic distortion, IMD, Third-order intercept, etc. Efficiency?

Good Luck!


Top

Guest
Post subject: Posted: Wed Aug 24, 2005 3:29 am
1-50-250MHz
2-Single ended, Class A
3-TOI 10dB higher than P1dB
3-P1dB is 5W
4-Biased at 24V,800mA



Posted  11/12/2012
withwave microwave devices - 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