RIGOL Technologies (test equipment) - RF Cafe
Exodus Advanced Communications Best in Class RF Amplifier SSPAs

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!
Anatech Electronics

Peak Power Detector Circuit - 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: Peak Power Detector Circuit Posted: Sun May 14, 2006 10:44 pm


Joined: Mon Apr 10, 2006 12:43 pm
Posts: 25
Good day. I am looking for information on peak power detectors.

It is my understanding that what makes a peak detector work is more of a timing issue then anything else. For example the burst of RF energy that needs to be measured is about 5 mS in length with a 100 mS off time between bursts. Now the detector does not have a long time constant (the response time of the diode is on the order of 100 nS). So the ADC needs a trigger to begin conversion when there is an RF signal present.

Is this the basic premise of a peak power detector? Any additional information would be appreciated.

Thank you


Post subject: Peak power detectorPosted: Tue May 16, 2006 6:38 pm


Joined: Wed Feb 22, 2006 3:51 pm
Posts: 104

There are some assumptions in your posting that I'd like to clarify.

1. The output of the peak detector must be a digital word, with enough bits (whatever that is).
2. The signal you're working with is a pulse, or pulse-like.
3. The timing of the presentation of the ADC output bits isn't particularly important (in other words, the signal's amplitude is slowly varying, if it changes at all).
4. You're interested in pulse-to-pulse variation (perhaps?)

Peak power detectors are often implemented in analog circuitry, where time constants, pulse widths, pulse repetition rates, etc have a distinct bearing on circuit designs.

Good Luck!


Post subject: Peak power detectorPosted: Thu May 18, 2006 10:27 am


Joined: Mon Apr 10, 2006 12:43 pm
Posts: 25
Good day Fred. Thank you for your response.

For right now, I am looking for some general information about how to design a peak power detector.

Let me restate my position to help clarify what I am talking about.

I will have an RF signal that is pulsed. I need to be able to measure the power for each pulse. I have made a couple of assumptions that might be my problems

1) The response time of the detector is fast enough (for example 5 uS) and the pulse width is sufficient large (5 mS) so that there is no problem with the detector responding to the signal.

2) The output of the peak detector needs to go to an embedded processor so I need an analog-to-digital convertor.

3) The ADC I am using is fast enough (conversion time of 5 to 10 uS) that I do not need to worry about a sample & hold circuit>

Based on these assumptions, it is my understanding that I would need to somehow trigger the ADC at the correct time to get an accurate power reading.

Are my assumptions valid?

Fred - if you have some additonal information about designing peak detectors (websites, books, magazines, etc) I would very much appreciate any information you can provide.

Thank you for your time and help.


Post subject: Posted: Sat May 20, 2006 4:37 am


Joined: Sun May 14, 2006 8:53 pm
Posts: 17
Location: Earth
Take a look at Analog Devices' website (RMS detectors and log-amps). The following linkcontains very good documentation.

Posted  11/12/2012
Copper Mountain Technologies - RF Cafe
withwave microwave devices - RF Cafe
Amplifier Solutions Corporation (ASC) - RF Cafe

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

These Are Available for Free