[Antennas] Unity Gain?

[Christopher Boone]

A true "unity" gain antenna would have -2.15db compared to an actual
dipole.
but such an antenna does not exist..(also called isotropic it is
theoretical)
The antenna makers have never really settled on a standard...and when
the term "db" is used,
there IS no reference.....dbi is referenced to an isotropic and dbd is
referenced to a dipole..
as noted above, a 0dbi antenna would be -2.15dbd or a 0dbd antenna would
be +2.15dbi gain..
a 1/4wave whip is closer to 0dbd than anything else...but a piece of wet
spaghetti can be
12db of gain...BUT 12db compared to WHAT? ;) and the same goes for an
"unity" gain antenna

Chris
WB5ITT


> -----Original Message-----
> From: antennas-bounces at mailman.qth.net 
> [mailto:antennas-bounces at mailman.qth.net] On Behalf Of Dan Richardson
> Sent: Wednesday, June 23, 2004 9:45 AM
> To: antennas at mailman.qth.net
> Subject: [Antennas] Unity Gain?
> 
> 
>  From time to time an antenna manufactures will state that an 
> antenna has 
> "unity gain". It is my understanding that this term is used 
> for describing 
> antennas used in mobile applications and is referenced to the 
> gain of a 
> quarter-wave whip.
> Does anyone know of any instances where this term is used otherwise?
> 
> My reason for asking is that I have a so called unity gain 
> antenna, but 
> when comparing it to a standard quarter-wave whip it has much 
> less gain.
> 
> Danny, K6MHE