Thank you for visiting RF Cafe! Electronics World Cover,TOC,and list of posted Popular Electronics articles QST Radio & TV News Radio-Craft Radio-Electronics Short Wave Craft Wireless World About RF Cafe RF Cafe Homepage RF Cafe in Morse Code Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs Twitter LinkedIn Crosswords Engineering Humor Kirt's Cogitations Engineering Event Calendar RF Engineering Quizzes AN/MPN-14 Radar 5CCG Notable Quotes App Notes Calculators Education Magazines Software,T-Shirts,Coffee Mugs Articles - submitted by RF Cafe visitors Simulators Technical Writings RF Cafe Archives Test Notes Wireless System Designer RF Stencils for Visio Shapes for Word Search RF Cafe Sitemap Advertising Facebook RF Cafe Forums RF Cafe Homepage Thank you for visiting RF Cafe!

P1dB Definition - RF Cafe Forums

The original RF Cafe Forums were shut down in late 2012 due to maintenance issues. Original posts:

Amateur Radio | Antennas | Circuits & Components | Systems | Test & Measurement


ashishbondia
Post subject: P1dB definition Posted: Mon May 18, 2009 9:31 am

Captain


Joined: Wed Aug 16, 2006 8:20 am
Posts: 23
Location: India
Hi!
In the data-sheets the P1dB for an amplifier or mixer is defined for at single frequencies. Take the case of a UWB signal of say 500 MHz bandwidth centered at an LO signal of 4.9 GHz where have a power distribution such that all frequencies component from 4.65 GHz to 5.15 GHz have same amplitude level. Consider that the amplitude levels are just below the P1dB rating at the respective frequencies for a given amplifier.
my question is

1. Will the device saturate?
2. If yes then how do we find the maximum power that can be applied to the device input before it reaches saturation in the presence of such a signal?

_________________
Ashish Bondia,
Design Engineer- RF


Top

IR
Post subject: Re: P1dB definitionPosted: Mon May 18, 2009 8:23 pm

Site Admin


Joined: Mon Jun 27, 2005 2:02 pm
Posts: 373
Location: Germany
Hi,

P1dB by definition is frequency selective, that means it is defined only per single frequency. If you want to know the P1dB characterstic of your amplifier for a wide band of frequencies, you have to measure it for each frequency.

If your BW is very wide, you can measure the P1dB for small frequency spacings and assuming that the device's flatness is relatively small, you can interpolate the P1dB for the frequencies in between.

saturation occurs after P1dB has been reached.

There is a term called back off, which is defined as

Backoff= P1dB(in)-Pin(actual)

Where:

P1dB(in) - is the P1dB level at the input (measured).
Pin(actual) - actual provided input power.

If the backoff which you get is positive, then you are away from P1dB and therefore far from saturation.

_________________
Best regards,

- IR


Top

yendori
Post subject: Re: P1dB definitionPosted: Tue May 19, 2009 10:56 am

General


Joined: Thu Sep 25, 2003 1:19 am
Posts: 50
Location: texarcana
Is it possble to add the tone power to LOG(N).?

N= number of channels







Posted  11/12/2012

RF Cafe Software

   Wireless System Designer - RF Cafe
Wireless System Designer

RF & EE Symbols Word
RF Stencils for Visio
Calculator Workbook
RF Workbench
Smith Chartâ„¢ for Visio
Smith Chartâ„¢ for Excel

About RF Cafe

Kirt Blattenberger - RF Cafe WebmasterCopyright
1996 - 2022
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 Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...

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

Try Using SEARCH
to Find What You Need. 
There are 1,000s of Pages Indexed on RF Cafe !

height-line