TITLE: The Response of GPS Antennas - How Design, Environment, and Frequency
       Affect What You See
                                                  
AUTHOR Bruce R. Schupler
       Honeywell Technology Solutions, Inc.

There are many factors which may influence the performance of GPS antennas.
These include differences in the design of the antennas, manufacturing
variability between antennas of the same model, the material which surrounds
the antenna (including the antenna mount and radome), and the frequency
range over which the antenna is used.  As part of an ongoing program of
antenna measurement, we have characterized a large number of GPS antennas in
the anechoic chamber at GSFC in a variety of configurations. This paper will
show examples of how these factors affect the amplitude and phase
performance of a variety of antennas.