You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
The Feb 2025 Radioddity Giveaway Results are In! Click Here to see who won!

Reply to thread

Message

I'm trying to verify empirical antenna gain figures and in the context of microwave frequencies, where I think ground effects are of less concern that typical at HF.

I come across a HT "duck" antenna (5.4 GHz) that states it as a quarter wave with unity gain. How would this be expressed as dBi? Can I first assume unity here means 0 dBq? I wonder because I've also seen unity to imply equal to an isotropic, and also to a free space dipole...?

How does dBq then relate to dBi? I read the Wikipedia article that states a quarter wave antenna has 3 dBd gain. I've read that elsewhere too, but I've also read that a quarter wave whip has loss relative to a reference dipole. ?

https://en.wikipedia.org/wiki/Dipole_antenna

The bolded statement seems to contradict the entire section, however. I also wonder of the validity of this in the context of this "duck" antenna, since there may well be near perfect ground. So is it even possible to make any associations to relative gain figures here? I've read that quarter wave antennas have basically equal gain as a dipole.

It is already well established that 2.15 dBi = 0 dBd, at least I am not considering ground effects and that a dipole actually has ~8 dBi gain...

<blockquote data-quote="C2" data-source="post: 528579" data-attributes="member: 568">I&#039;m trying to verify empirical antenna gain figures and in the context of microwave frequencies, where I think ground effects are of less concern that typical at HF.I come across a HT &quot;duck&quot; antenna (5.4 GHz) that states it as a quarter wave with unity gain. How would this be expressed as dBi? Can I first assume unity here means 0 dBq? I wonder because I&#039;ve also seen unity to imply equal to an isotropic, and also to a free space dipole...?How does dBq then relate to dBi? I read the Wikipedia article that states a quarter wave antenna has 3 dBd gain. I&#039;ve read that elsewhere too, but I&#039;ve also read that a quarter wave whip has loss relative to a reference dipole. ?&nbsp;<a href="https://en.wikipedia.org/wiki/Dipole_antenna" target="_blank">https://en.wikipedia.org/wiki/Dipole_antenna</a>The bolded statement seems to contradict the entire section, however. I also wonder of the validity of this in the context of this &quot;duck&quot; antenna, since there may well be near perfect ground. So is it even possible to make any associations to relative gain figures here? I&#039;ve read that quarter wave antennas have basically equal gain as a dipole.It is already well established that 2.15 dBi = 0 dBd, at least I am not considering ground effects and that a dipole actually has ~8 dBi gain...</blockquote>

[QUOTE="C2, post: 528579, member: 568"] I'm trying to verify empirical antenna gain figures and in the context of microwave frequencies, where I think ground effects are of less concern that typical at HF. I come across a HT "duck" antenna (5.4 GHz) that states it as a quarter wave with unity gain. How would this be expressed as dBi? Can I first assume unity here means 0 dBq? I wonder because I've also seen unity to imply equal to an isotropic, and also to a free space dipole...? How does dBq then relate to dBi? I read the Wikipedia article that states a quarter wave antenna has 3 dBd gain. I've read that elsewhere too, but I've also read that a quarter wave whip has loss relative to a reference dipole. ? [URL]https://en.wikipedia.org/wiki/Dipole_antenna[/URL] The bolded statement seems to contradict the entire section, however. I also wonder of the validity of this in the context of this "duck" antenna, since there may well be near perfect ground. So is it even possible to make any associations to relative gain figures here? I've read that quarter wave antennas have basically equal gain as a dipole. It is already well established that 2.15 dBi = 0 dBd, at least I am not considering ground effects and that a dipole actually has ~8 dBi gain... [/QUOTE]

Top Bottom