Breaking News
Comments
Newest First | Oldest First | Threaded View
Cezar Palconet
User Rank
Rookie
re: Radiated efficiency: A true measure of antenna performance
Cezar Palconet   1/12/2011 10:20:20 AM
NO RATINGS
The title say’s “ Radiated Efficiency : a true measure of antenna performance ” This is an interesting paper and deserves further thought, in any measure, it is always a comparison between two values, where one may be an accepted standard. In this article I have not seen any agreement to the later as being accepted as a value, in theory, antennas of the same configuration in terms of electrical and physical, will exhibit very close if not identical performance values, setting this aside, but not completely losing sight of it, a focus on determining what the title says, I agree that the amount of efficiency for an antenna is the ratio of how it efficiently radiates the power delivered to its feed point, thus a reference antenna would have to be conceived for this purpose, one that has a material superior above all others, and a physical configuration that will represent a true Omni radiation pattern, specifically under laboratory conditions. Theoretically an isotropic reference antenna would fill this spot, however in that theory it did not mention the material that will exhibits such characteristics, thus in the real world, no two isotropic antenna of two material, of the same physical shape produce the same radiation characteristics efficiency. Gain is an element of physical configuration, thus for any specific applications where miniaturization and aesthetics are an issue, the unit gain will be compromised.

Bill.St.John
User Rank
Rookie
re: Radiated efficiency: A true measure of antenna performance
Bill.St.John   12/15/2010 10:49:05 PM
NO RATINGS
Actually David, a dipole has 2.1 dB gain over an isotrope. Bill

Fabrico
User Rank
Rookie
re: Radiated efficiency: A true measure of antenna performance
Fabrico   12/14/2010 6:43:13 PM
NO RATINGS
Can I have the permission to translate that into french with pictures?

David Ashton
User Rank
Blogger
re: Radiated efficiency: A true measure of antenna performance
David Ashton   12/14/2010 9:46:01 AM
NO RATINGS
Jouni - just looking at the diagram on page 3 (of the PDF)- it appears that even in the direction of maximum radiation a dipole has very little gain over an isotropic antenna - one dB or so at the most??

David Ashton
User Rank
Blogger
re: Radiated efficiency: A true measure of antenna performance
David Ashton   12/14/2010 9:39:50 AM
NO RATINGS
Txema: From the article: "Antenna absolute gain is defined as the ratio of the radiation intensity in a given direction to the radiation intensity that would be obtained if the power accepted by the antenna were radiated evenly to all directions of surrounding space (i.e. isotropically)" Makes sense to me. Also it's important to distinguish between gain relative to a dipole or relative to a (hypothetical) isotropic antenna Hence the dBi used in the diagram on Page 4 (of the PDF). Some antennas (eg the quoted "monopoles with parasitic elements") may radiate in a pattern that is equally strong in all HORIZONTAL directions. So you might get a radiation pattern that is like a much flatter doughnut than that shown on Page 3 (again of the PDF). Jouni - could you say that antenna efficiency is the ratio of the actual radiated power in the direction of interest (usually that of max. radiation) divided by the theoretical predicted radiated power in that direction? and what sort of figures would you find in practice? Great article - thanks! (and RF ed - thanks for the PDF link)

Jouni Lifländer
User Rank
Rookie
re: Radiated efficiency: A true measure of antenna performance
Jouni Lifländer   12/14/2010 8:16:14 AM
NO RATINGS
The gain provides a single fiqure which determines antennas capability to radiate towards some specific direction and thus it doesn't tell whether the radiation is equally distributed towards all directions or not. If the signal is equally strong in all directions, the radiation pattern is omnidirectional. In practice such antenna has some gain value less than 0dB. An isotropic antenna is an hypothetical lossless antenna having equal radiation in all directions. Such lossless antennas exists only in theory.

t.alex
User Rank
Rookie
re: Radiated efficiency: A true measure of antenna performance
t.alex   12/9/2010 8:26:12 AM
NO RATINGS
Very well written article. I really enjoy the explanation of gain - which is misleading for most users.

Kinnar
User Rank
CEO
re: Radiated efficiency: A true measure of antenna performance
Kinnar   12/9/2010 8:19:34 AM
NO RATINGS
This is quite true that Radiated Efficiency is the true measure of the Antenna but in case of the Handhelds and Notebooks it is better if consumer can come to know about the property of the antenna, but generally they never come to know about this. Even the laptops does not come with the reception pattern or radiation pattern of the antenna.

Txema
User Rank
Rookie
re: Radiated efficiency: A true measure of antenna performance
Txema   12/8/2010 10:37:19 AM
NO RATINGS
"Even if the signal is equally strong in all directions, gain doesn’t provide a measure to determine that"...confusing... if the signal is equally strong in all directions, then it is an isotropic pattern, and gain should be 0dB... Or am I misunderstanding something?

JanineLove
User Rank
Blogger
re: Radiated efficiency: A true measure of antenna performance
JanineLove   12/7/2010 1:29:47 PM
NO RATINGS
I asked Pulse for the text of this white paper because it is a good, general description of important performance parameters.The original can be downloaded here. http://www.pulseelectronics.com/file.php?id=3720



EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Max Maxfield

Aging Brass: Cow Poop vs. Horse Doo-Doo
Max Maxfield
7 comments
As you may recall, one of the things I want to do with the brass panels I'm using in my Inamorata Prognostication Engine is to make them look really old. Since everything is being mounted ...

EDN Staff

11 Summer Vacation Spots for Engineers
EDN Staff
11 comments
This collection of places from technology history, museums, and modern marvels is a roadmap for an engineering adventure that will take you around the world. Here are just a few spots ...

Glen Chenier

Engineers Solve Analog/Digital Problem, Invent Creative Expletives
Glen Chenier
11 comments
- An analog engineer and a digital engineer join forces, use their respective skills, and pull a few bunnies out of a hat to troubleshoot a system with which they are completely ...

Larry Desjardin

Engineers Should Study Finance: 5 Reasons Why
Larry Desjardin
45 comments
I'm a big proponent of engineers learning financial basics. Why? Because engineers are making decisions all the time, in multiple ways. Having a good financial understanding guides these ...

Flash Poll
Top Comments of the Week
Like Us on Facebook
EE Times on Twitter
EE Times Twitter Feed

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)