Re: NEC-LIST: Definition of Gain

>So here are several questions:
>
>1) Do you believe that the definition of gain (of an antenna), when
>used with no qualifying adjective, should include mismatch loss or be
>defined in terms of a complex conjugate matched antenna?
>
>2) Do you believe that polarization mismatch in a link budget context
>should be part of the definition of gain or treated separately?
>
>3) Do you believe that the definition of gain for a receive antenna
>should be the same as for a transmit antenna?

George,

My recommendation would be to stick to what's in the authoritative
works on the subject (e.g. Kraus, Jasik, Jordan, King, Terman, etc.).
To that end, my answers would be:

1) Neither. Antenna gain by definition does not (and should not)
depend on source (transmitter) or sink (receiver) characteristics. If
you want to include those, then the antenna becomes a component of a
system and you would be referring to a system (or perhaps "operating")
gain. The antenna might incorporate such "non-antenna" components as
matching networks and filters. The important thing is that what we're
calling the antenna feedpoint (antenna terminals) be identified.

2) Treated separately.

3) Why should it be different?

IMHO, the textbook definitions and measurement procedures of antenna
gain seem to be in agreement and continue to be viable.

With regard to the efficiency issue, you have to consider all
resistive losses forward of the designated antenna terminals exclusive
of the radiation resistance. These include the antenna structure
proper and any additional resistive losses (e.g. ground losses in the
immediate vicinity of the antenna) imposed by the operating
environment. Again, I don't see the need for a revised(?) definition
of efficiency.

Frankly, I don't see way any of this should be a problem to anyone
familiar with antennas and antenna theory.

-- 
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