Diversity Antenna Design Requirements (Mc57Xx / Mc8780 / Mc8781 / Mc8785V / Mc8790 / Mc8790V / Mc8791V / Mc8792V); Gps Antenna Design Requirements (Mc57Xx / Mc8775V / Mc878X) - Sierra Wireless MC5725 Hardware Integration Manual

Rev 1.9.1 Feb.09
In the event of a discrepancy in values between this guide and the Product Specification Document (PSD), the PSD takes precedence.
Diversity antenna design requirements
(MC57xx / MC8780 / MC8781 / MC8785V /
MC8790 / MC8790V / MC8791V /
MC8792V)
Antenna diversity is required for end user performance and
enhanced coverage on CDMA networks (800 MHz /
1900 MHz) for MC57xx, and on UMTS networks (850 MHz /
1900 MHz / 2100 MHz) for MC8780 / MC8781 / MC8785V /
MC8790 / MC8790V / MC8791V / MC8792V. (See Table A‐3 on
page 102 for UMTS diversity support by module.)
In addition to passing the specific tests described in Testing
beginning on page 106, the diversity path antenna should
satisfy the following requirement:
Receive performance, measured by forward link
•
throughput, must be 0 to 3 dB better than a single antenna
Performance goals
When designing the antenna system, consider the following
performance goals:
0dB gain antenna (or better)
•
Diversity antenna receive performance to be similar to
•
primary antenna
Separation distance or polarity separation to achieve
•
diversity antenna isolation of 10db (minimum)—otherwise
the receive antenna picks up too much power radiating
from the primary antenna
GPS antenna design requirements
(MC57xx / MC8775V / MC878x)
A second antenna is required to access GPS functionality—if
the modem also supports diversity, the same antenna can be
used.
In addition to passing the specific tests described in Testing
beginning on page 106, the diversity path antenna should
satisfy the following requirements:
• Field of view (FOV): Omni‐directional in azimuth, ‐45
°
+90 in elevation
Polarization (average Gv/Gh): > 0 dB. Vertical linear polar‐
•
ization is sufficient (no need to optimize for circular polar‐
ization)
Free space average gain (Gv+Gh) over FOV: > ‐6 dBi
•
(preferably > ‐3 dBi). Note: Average gain is the sum of
average values (Gv + Gh) where both Gv and Gh are
Proprietary and Confidential
Antenna Specification
°
to
105