User`s guide

Chapter 4 - Antenna Descriptions
Hawk 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 along a fixed azimuth (in a vertical cut) is displayed in
the following figure. The gain pattern clearly indicates that the Hawk 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 full 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 4.2: Typical Motorola HAWK Antenna Gain Pattern
Motorola GPS Products - M12+ User's Guide Revision 6.X 09FEB05
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