My 2 cents,
>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?
In essence, an antenna is a two port device that provides a match
between a transmission line impedance, typically 50 ohms, and free
space wave impedance, typically 377 ohms. The input port is described
in terms of input impedance and voltage standing wave ratio (VSWR),
while the output port is described in terms of directivity and
radiation pattern, overall performance of both ports is described by
efficiency. The efficiency is a function of many terms (conductivity
of antenna, mismatch, ground, etc) to determine gain. All these
factors must be accounted for to determine gain. One always must look
close an vendor's specifications to see how gain is defined - dBi in
free space, perfect ground plane, and sometime even the vague term dB
with no reference.
With antenna technology changing to include distributive component we
must include insertion loss in antenna efficiency, hence in the gain
definition.
>2) Do you believe that polarization mismatch in a link budget context
>should be part of the definition of gain or treated separately?
Gain should be divided into separate components.
>3) Do you believe that the definition of gain for a receive antenna
>should be the same as for a transmit antenna?
Gain should be the same, but often efficiency and directivity are
required as separate values.
Received on Tue Mar 07 2000 - 04:26:40 EST
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