Anatech Electronics (RF Filters) - RF Cafe
LadyBug Technologies LB480A RF Power Sensor - RF Cafe

About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024
    Kirt Blattenberger,


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:

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!
Innovative Power Products Couplers

signals in phase - 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

Post subject: signals in phase
Unread post Posted: Fri Feb 11, 2005 6:39 am

Joined: Fri Feb 11, 2005 6:32 am
Posts: 4
hi everybody,

I have a question:
I have two signal generators. I´d like to make two signals 1900MHz with a phase between them. In the generators there is a option where you can chenge the starting phase. If I put this two signals made in a power combiner in your opinion they will be stable in phase. I mean the different phase between them will be always the same. Of course they are syncronized

Thanks in advance, wallace0075


Post subject:
Unread postPosted: Fri Feb 11, 2005 9:00 am

The two signals will maintante the same phase difference + the phase error of the splitter. But you can calibrate out the phase error by adjusting the phase of one of the signals to compensate for the phase error of the combiner.


Post subject: Phase shift
Unread postPosted: Sat Feb 12, 2005 1:50 pm


Just because 2 signals are at the same frequency doesn't mean that the phase shift between them can't vary. Noise in one generator that isn't in the other will show up as a phase shift between the two.

To put it another way: in a phase-locked-loop, the phase error is the signal that provides the feecback which tunes the VCO. So unless the generators use a 3rd order loop, there will be a phase error in each generator, which will change with temperature, voltage, etc.

So you absolutely *MUST* verify that your generators will do what you want.

Good Luck.


Post subject:
Unread postPosted: Mon Feb 14, 2005 10:40 am

I thought what wallace was trying to achieve here was to have to signals of same frequency but different phase. Depending on what he has a generator, there are many that are capable of adjusting the phase of the signal. Naturally, he will need to calibrate the signal to cancel out errors in the system.


Post subject:
Unread postPosted: Tue Feb 15, 2005 3:43 am

I have an idea abot this.
If I put a trigger with the same frequency of the two signals that I want get, and I sincronyze all, Can I get in the output the two signals stable in phase ??



Post subject:
Unread postPosted: Tue Feb 15, 2005 4:15 am

I have an idea abot this.
If I put a trigger with the same frequency of the two signals that I want get, and I sincronyze all, Can I get in the output the two signals stable in phase ??


Posted  11/12/2012
Copper Mountain Technologies - RF Cafe
PCB Directory (Assembly)
LOTUS Communications Systems Modular RF Component Building Blocks - RF Cafe

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

These Are Available for Free