dBi Meaning in Wi-Fi Antennas: How Antenna Gain Affects Wireless Signal Strength

I'm a bit green and have a problem.
I bought a wi-fi antenna and the dBi parameter is given for each antenna. apparently it is some kind of energy gain factor, but I don't really know what it is. All I know is that the bigger the better. please answer thanks in advance. :sm11:

There was a thread a while back where this topic was discussed:
https://www.elektroda.pl/rtvforum/topic69352.html

Hello and welcome.

In this particular case, dBi determines the gain of the antenna relative to the isotropic antenna. It is such an ideal, theoretical antenna radiating completely omnidirectionally. Giving the gain in relation to an isotropic antenna is a marketing ploy usually aimed at improving the parameters of the antenna in the eyes of the buyer. More reliable is the gain given in dB in relation to a simple dipole. Only that in this case, the reported gains for antennas used in WiFi devices would often be around zero or even negative. From a commercial point of view, it would look at least poorly. Different manufacturers give different information, as a result, sometimes a better antenna has a smaller declared gain ...

sebastian

ArtMedia wrote:

In this particular case, dBi determines the gain of the antenna relative to the isotropic antenna.

Not only in this. In any case.

ArtMedia wrote:

It is such an ideal, theoretical antenna radiating completely omnidirectionally.

The term "omnidirectional" suggests one plane, while an isotropic antenna radiates omnidirectionally.

ArtMedia wrote:

Giving the gain in relation to an isotropic antenna is a marketing ploy usually aimed at improving the parameters of the antenna in the eyes of the buyer.

Not exactly. A marketing ploy is giving the antenna gain in decibels, without specifying whether this gain applies to an isotropic antenna or a dipole.

ArtMedia wrote:

More reliable is the gain given in dB in relation to a simple dipole.

Both are equally valid as long as you specify whether you mean dBi or dBd.

You're wrong, not everyone. You can drily answer that it is a conventional unit of profit. It's just not about that. This is to help the "green"...
In addition, the term "in this particular case" does not negate that in another as well.

The term omnidirectional exhausts the subject completely. No need to add omnidirectionally. Even my "totally" is unnecessary. Playing with semantics serves no purpose. You can add something so that someone unfamiliar with the topic better understands the intention of the helper. For example, that it radiates the same way in every direction.

Regardless of the reference, it's a marketing ploy.

Both are authoritative, for someone who knows what that means. For a mass customer, this is "eyewashing". It is irrelevant to the questioner.

The forum is supposed to be for mutual help, not smarting? Unless I'm wrong? If so, someone please correct me. If you want to be precise, do it well, precisely.

sebastian

Dude ArtMedia! Read at least one decent book on the basics of antenna technology, learn the terminology, then we'll have something to talk about. You cannot replace reliable knowledge with an aggressive tone of speech.

ArtMedia wrote:

The term omnidirectional exhausts the subject completely. No need to add omnidirectionally. Even my "totally" is unnecessary. Playing with semantics serves no purpose.

The term "omni-directional", yes, completely exhausts the subject, but omni-directional antennas. An omnidirectional antenna is definitely not an isotropic antenna. The radiation pattern of an omnidirectional antenna resembles a donut, while the pattern of an isotropic antenna is a sphere. An example of an omnidirectional antenna is a vertically mounted dipole. I hope you won't claim that a dipole and an isotropic antenna are the same thing, as it would follow from your reasoning...
As you can see, this game of semantics you're playing here really serves no purpose.

ArtMedia wrote:

The forum is supposed to be for mutual help, not smarts? Unless I'm wrong? If so, someone please correct me. If you want to be precise, do it well, precisely.

I wholeheartedly agree with you.

Hello again.

I wonder where the aggression is here? Unless on your part? I know exactly what I am writing about, but I do not forget to whom I am answering. Appropriate semantics are highly recommended here. If you don't use it, you won't help the questioner. Instead of being smart, help yourself. Your statement adds nothing. Of course, it is easiest to simplify the matter and say that an omnidirectional antenna is, for example, a simple dipole. But why do you use the term omnidirectional antenna then? It's just semantics. So if you pick on my simplification, why use a similar one yourself.
I have not made any argument here about what you accuse me of.
As for the term itself, however, you are wrong. An omnidirectional antenna is also an antenna that radiates omnidirectionally in several planes. Also on all levels. Of course, the term omnidirectional is usually used to refer to antennas radiating omnidirectionally in the horizontal plane. Just consider how the "dry" term "isotropic" would help the questioner?
Again, if you want to be specific, be precise and to the point. I have nothing against. By describing the same thing using different semantics you start feeding the TROLL.

sebastian

Well... Hands down...

ArtMedia wrote:

As for the term itself, however, you are wrong. An omnidirectional antenna is also an antenna that radiates omnidirectionally in several planes. Also on all levels.

In other words, a sphere is a circle! Well, to be precise: infinitely many circles combined with rotation about an axis lying in the plane of the circle and passing through its center. Incredibly elegant reasoning!
According to this theory, the YAGI antenna is also an omnidirectional antenna (taking into account the side lobes and the retrograde). congratulations!

The difference between an omnidirectional and an isotropic antenna is similar to the difference between a circle (hence "omnidirectional") and a sphere.

If anyone wants to check who of us is right and who is wrong, there are books in which these fairly basic concepts are discussed:
1. "Antennas and propagation of radio waves" - Daniel Józef Bem
2. "Waves and Antennas" - Jarosław Szóstka
3. "Amateur HF and VHF antennas" - Zdzisław Bieńkowski, Edmund Lipiński
...and probably a whole lot of others.

ArtMedia wrote:

I know exactly what I am writing about, but I do not forget to whom I am answering.

Well ... I am surprised that you are so critical of the intellectual abilities of a colleague asking for help. I believe that he is able to distinguish a "bagel" from a "ball".

If ArtMedia's colleague is still convinced that he is right, I'm afraid that no argument can change this conviction. Anyway, I consider the topic exhausted.

Hello again.

Anyone who thinks that they will learn something more about the title topic in this thread, I must immediately worry. It's been completely OT for a while now.
I will gladly continue the discussion.
Very often I repeat, "it is not enough to read, you also need to understand, reflect and think about what you have read". The mere thoughtless duplication of information without going too far into the content leads to certain mental "blips on the eyes". Reading many forums, groups and mailing lists, one can get the impression that they exist only so that their participants can flash knowledge. Whether they help or not doesn't matter. Not only do they not help, but they also perpetuate the already repeated incorrect mental shortcuts in the literature. These abbreviations may be understandable to people familiar with the subject, but they are completely useless and misleading to people who ask, who do not always know what they are asking. It's the same here.
Referring to specific examples, I would like to quote a sentence:
" An omnidirectional antenna is definitely not an isotropic antenna. The radiation pattern of an omnidirectional antenna resembles a donut, while the pattern of an isotropic antenna is a sphere.
"
Of course, no antenna is isotropic, but an isotropic antenna would be an omnidirectional antenna if it existed! Because it is only theoretical, it is also theoretically omnidirectional. Calling the radiation pattern of an omnidirectional antenna a bagel is at least debatable. However, calling the radiation pattern of an isotropic antenna a sphere, and then calling it a sphere, is pyramidal nonsense. This is how the uncritical duplication of drawings noticed in the literature ends.
Then what about other types of omni-directional antennas with multiple lobes? Again, please, if you want to be specific, do it exactly.
The evidence you cite that I claim that a sphere is a circle is also wrong. If you have actually read the books you mention, you should know the difference between directional and omnidirectional antennas. These are two different groups of antennas.
Your theorem about the difference between an omnidirectional and an isotropic antenna can also be put between fairy tales. An isotropic antenna falls under the classification of omnidirectional antennas, but no existing omnidirectional antenna is an isotropic antenna. It's like a square. Every square is a rectangle, but not every rectangle is a square...
You make the mistake of not trying to assess the intellectual abilities of the questioner. This is how you make yourself the "alpha and omega". The questioner still does not know.
I always try to assess these possibilities and provide answers at the appropriate level. I can be wise with another wise man.
Having any knowledge about antennas, the topic cannot be considered exhausted. This polemic is too short to exhaust it. I look forward to further constructive suggestions.
BTW: Only can you change the thread?

sebastian