Huawei EM770 - Design Recommendations

HUAWEI EM770 HSPA PC Embedded Module V100R001
Product Specification
Issue 1
(2008-09-15)
Huawei Confidential: This documents is Huawei Proprietary and Confidential(NDA
Required).It may not be duplicated, neither distributed externally without
prior and written permission of Huawei.
Page
34 of 68
Table 4-5 Recommended index of the auxiliary antenna
Working frequency 869–894 MHz, 1930–1990 MHz, and 2110–2170 MHz
Port impedance 50 Ohm
Port standing wave < 2.5
Peak gain > –3 dBi
Antenna efficiency > 30%
Polarization Linear polarization
Pattern Omnidirectional
Table 4-6 Recommended index of the isolation between the main antenna and the
auxiliary antenna
Antenna isolation < –10 dBi
The recommended isolation between the module antennas and other PC antennas is
as follows:
Because the PC has other internal antennas such as the WLAN antenna, to ensure
the proper operation of each communication system, requirements on antenna
isolation between different communication systems should be considered. Table 4-7
lists the recommended index of the antenna isolation.
Table 4-7 Recommended index of the isolation between the module antennas and other
PC antennas
Antenna isolation < –20 dBi
4.3.2 Design Recommendations
Recommendations for Designing the Module Antennas
The design recommendations are as follows:
1. It is recommended that the module antennas are designed at the upper edge,
left edge or right edge of the PC screen. Designing the antenna at the upper
edge is better.
2. When designing the main antenna and the auxiliary antenna, the requirement on
the antenna isolation should be considered (the recommended value is listed in
Table 4-6). Meanwhile, try to keep the distance between the main antenna and
the auxiliary antenna as large as possible for optimizing the space diversity. For
example, you can place the main antenna at the upper left corner of the PC
screen and place the auxiliary antenna at the upper right corner of the PC
screen.
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