User`s guide

Chapter 4 - Antenna Descriptions
Timing2000 Antenna Gain Pattern
The sensitivity of an antenna as a function of elevation angle is represented by the gain pattern.
Some directions are much more appropriate for signal reception than others, so the gain
characteristics of an antenna play a significant role in the antenna's overall performance.
A cross-sectional view of the antenna gain pattern for the Timing2000 along a fixed azimuth (in a
vertical cut) is displayed in the following figure. The gain pattern clearly indicates that the antenna
is designed for full, upper hemispherical coverage, with the gain diminishing at low elevations.
This cross-section is representative of any vertical cross section over a 0 to 360 degree azimuth
range and thus, the 3 dimensional gain pattern is a symmetric spheroidal surface. It is important
to note that this gain pattern varies in elevation angle, but not in horizontal azimuth. This design is
well suited for many GPS applications, accommodating full sky coverage above the local horizon
and minimizing ground reflected multipath effects.
Figure 4.9: Typical Antenna Gain Pattern for ANT GCNTM20A3A
Motorola GPS Products - M12+ User's Guide Revision 6.X 09FEB05
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