NEC-LIST: Definition of Gain

I currently chair the IEEE Antenna Standards Committee, and we are
working on revising the IEEE Std 145 on antenna definitions. One topic
that has received lively discussion is the definition of gain. All
agree that gain can be determined as the product of the efficiency and
the directivity. The issue is "what all should go into the
efficiency?". Some would like to include mismatch loss and others
want a complex conjugate match.Also, the current definition of "power
gain" is deprecated in favor of "absolute gain." Javier's question
today is what prompted me to ask nec-list for opinions. Finally, there
is the matter of how to treat polarization (if at all) in definitions
of gain. The current IEEE definitions define "partial ...gain" as a
way of dealing with this issue of polarization, but I dont see this
usage in papers being published these days.

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?

There are three ways to look at these questions: how you feel about it
personally, what do you do now regarding these definiton matters, and
what you believe to be "most common usage today." I would appreciate
your answer from all three standpoints.

Thank you for considering this matter.

Sincerely,

George H. Hagn
Chair, IEEE Antenna Standards Committee (ASC)
Chair, IEEE ASC Subcommittee on Definitions
Received on Thu Mar 02 2000 - 13:22:38 EST